and boiled in water until the solution is found to gelatinize firmly on cooling. The impurities are allowed to settle, and the residuum to gelatinize in shallow wooden boxes; it is then cut into slices and dried upon nets. Good glue is semi-transparent, and free from spots and clouds. Marine glue, a composition used for cementing materials that are exposed to moisture, is made by dissolving 1 part of indiarubber in 12 parts of mineral naphtha, and adding 20 parts of powdered shellac; it resists wet, and cements glass and metals as well as wood. Fish glue is made from the skins of fluke and other flatfish and the bladders and offal of any kind of fish. The product is a very strong adhesive, but needs deodorizing; this is accomplished by adding about 1 per cent of sodium phosphate together with one-fourth of 1 per cent of saccharin. White fish-glue, or diamond cement, is made of isinglass dissolved in alcohol. Before use on important work glues are subjected to tests for moisture and ash; for acidity; for contained fat; for gelatine content; for water absorptive capacity; besides several tests of the jelly as to adhesive power, viscosity, tensile strength and tendency to foam (because of included peptones).

The glue industry in the United States was founded by Peter Cooper in 1827, when he established a factory in Brooklyn. About the same time a factory in Philadelphia was started by Charles Baeder and William Adamson. At present glue factories are centralizing near the great slaughter-houses of the Middle West, the sources of raw supplies, and the larger packing concerns, notably the Armours and the Swifts in Chicago and the Cudahy Company in Omaha, have their own glue plants. (See PACKING INDUSTRY.) The factories still in the East are largely supplied with imported hides. The export trade is steadily growing and has passed the $500,000 mark per annum. France alone surpasses America in the quality of its finer glues, and these are imported for use in making straw hats. The finest glues made in the United States are prepared from sinews, and it is likely that continual experiment upon them will result in a product equal to the best imported from France.

GLUME. See GRASSES.

GLUT-HERRING, or BLUEJACK, a herring (Pomolobus æstivalis), abundant in the Southern States, and very similar to the alewife (q.v.), but is more elongated, is darker on the back and has a black peritoneum and comparatively small eyes. The quality of its flesh is poor.

GLUTEN (Lat., glue), that part of the protein content of wheat which is insoluble in water. It is a combination of the two proteid substances gliadin and glutenin, the first containing 17.66 per cent of nitrogen, and the second, 17.49 per cent. These components, however, do not combine in the wheat kernel, nor in wheat flour to form gluten: it requires the presence of water to initiate the combination. Gluten is insoluble in water containing salts, but the gliadin component is soluble in distilled water and also in alcohol. As found

in wheat flour dough, gluten consists of about two-thirds gliadin and one-third glutenin, and it is this constituent of wheat flour which

causes the dough to be sticky, entrapping the bubbles of gas from the fermentative action of the yeast, or from the chemical action of baking-powder, and "lightening" the dough into a "sponge." Some glutens are tough and elastic, others soft and "rotten." The latter lack the quality of absorbing water, and do not hold the sponge made by the yeast, thus making a poorer bread, and fewer loaves to the barrel of flour. The strength of a gluten depends upon the proportion of gliadin to glutenin, and also to the presence or absence of certain mineral salts. The so-called "hard" wheats and those grown in hot countries have a larger gluten content than the "soft" wheats, or those grown in cold climates. The amount of gluten from any sample of flour, also, increases with the hardness of the water used and with the time the dough is permitted to stand, this increase ranging up to more than 6 per cent. The relative elasticity of the glutens in different samples of flour is sometimes tested with an instrument called the aleurometer, which operates on the expansion of wet gluten when exposed to a temperature of 300° F., but this test fails in the vital point that the value of a gluten depends not on its quantity, but on its quality. Of two samples of flour containing equal parts of gluten, one may be worth in bread-making more than twice the value of the other.

To obtain gluten from wheat, the grain is reduced to dough, and the starch removed by mechanical processes, the resultant product being a gray sh, tough, elastic, sticky substance which, when rightly proportioned in its gliadinglutenin content, is capable of being drawn out into long bands or shreds, Crude gluten consists of about 74 per cent of gliadin and glutenin, 7 per cent of non-gluten proteins and the remaining 19 per cent of fat, carbohydrates, fibre and mineral salts. In the domestic operation of separating the gluten from flour for making gluten bread for diabetic patients, a "strong" flour is made into stiff dough with hard water. This is allowed to stand for about an hour. The dough is then kneaded in water in small portions usually placed in loose muslin bags, the starch escaping through the bag and producing a milky appearance in the water. The kneading is continued in successive waters until no more "milkiness"> washes out.

In its highest refinement, gluten exhibits a fine molecular structure, delicate and sensitive to atmospheric conditions, and requires, after separation, immediate handling in its preparation for food.

About 16 pounds of gluten is obtained from 200 pounds of wheat-flour. On account of its high content of nitrogen, gluten soon deliquesces, sours and spoils after the separation from the starch, and demands an immediate treatment if desired for food purposes. What are known as gluten feeds are by-products in the manufacture of starch and glucose from corn, and the dried residues from the distilling of spirituous liquors. They have a nutritive value about equal to brewer's grains. To the glucose and starch makers corn consists of starch, gluten, germ and bran, all but the starch being by-products. They are separated by mechanical processes. The free germs of

the corn are dried, ground to meal, the oil extracted by solvents leaving oil-cake, a cattlefeed extensively used. The wet starch is run through vibratory sieves and over long wooden tables, the starch and gluten forming the mixture which passes through the sieves; the starch being deposited by gravity, the gluten liquid passes off at the ends of the tables. When evaporated, pressed and dried, this constitutes the gluten-meal of commerce. About five and one-half pounds is obtained from one bushel of corn.

The composition of gluten-meal is, protein 38 per cent, fat 3 per cent and starch 40 per cent. This is one of the richest and best feed products on the market. The nutritive value is very high, and the factor of digestibility ranges from 92 to 96 per cent. Gluten-meal is treated for the recovery of its starch, and gives two new products, a concentrated feedstuff, characterized by the large amount of proteids (60-70 per cent) it contains, and a maltose syrup. This feedstuff is suitable for animal consumption, and also for raising the percentage of proteids in feeds that have a small amount of these substances. When the wet bran, germs and gluten are mixed in the proportions as obtained from the original corn and the mixture dried, the resulting feed is known as gluten-feed. This is the most common feed product in the starch and glucose industry, and represents about 80 per cent of the by-product output. Its feeding value is very high, and its digestibility above 90 per cent. Its composition shows about 28 per cent protein and 3 per cent fat.

Corn oil-cake and gluten-meal are exported extensively. The bran and gluten feed is used almost exclusively in the United States. The production per bushel of corn is about 121⁄2 pounds of food, outside of the glucose or starch.

The waste product in the manufacture of starch or sugar is relatively much richer in oil and protein than is corn. Most factories are removing part of the corn-oil from the waste, so that nearly all the gluten-meals carry much less oil than they did a few years ago. Glutenfeeds differ from gluten-meals in that they contain a good deal of the corn-bran, and hence less of protein and digestible carbohydrates, and more of the indigestible woody fibre. The relation of gluten to bread making is set forth in detail in Bulletin No. 67, United States Department of Agriculture. The food value of gum-gluten has been outlined by Prof. Nelson Clark Parshall in a pamphlet published by the Pure Gluten Food Company, New York. Consult also Jago, W. C., The Technology of Bread-Making' (London 1911); United States Bureau of Chemistry, Bulletin 108, Feeding Stuffs of the United States) (Washington 1908).

GLUTTON, the English name in Europe of the large fur-bearing badger-like animal known in North America as wolverine (q.v.). It was renowned in mediæval literature for its excessive greed; hence the English words "glutton" and its derivatives. The alleged greed is, however, a matter of fable far more than of fact, yet gross exaggerations of the animal's voracity and sagacity survived even in educational books until very recent times. That it has in reality a quite extraordinary strength and

cunning, giving some foundation for the superstitious history, will be seen by reference to the article WOLVERINE.

GLYCERINE, or GLYCEROL. In 1783 Scheele showed that by acting upon olive oil by oxide of lead a substance may be obtained which has a sweetish taste; and in the following year he showed that the same substance may be had by acting in a similar manner upon other oils and fats, such as butter. He also observed that the substance in question may be obtained in the form of a syrupy fluid; that although it has a sweetish taste like sugar, it cannot be fermented; and that although it gives oxalic acid by oxidation, it differs from sugar in many respects. He failed, however, to ascertain its true relation to the oils which furnish it, and to the lead plaster (or "lead soap") which accompanies its formation. The true explanation of the reactions was given some 30 years later by Chevreul, as a result of his famous researches upon the animal fats, which were begun about 1811, and were concluded about 1823. In the course of these researches Chevreul showed that an animal fat consists, in general, of a mixture of several definite chemical substances, each of which is itself a fat, and each of which consists of Scheele's sweetish substance. (which is now called "glycerin"), combined with an organic acid. When the fat is treated with an alkali, or with lime or oxide of lead, the organic acid that is present combines with the alkali, or the lime, or the lead, to produce a new substance called a "soap," the organic base (glycerin) which was previously combined with the acid being thereby set free. Since the time of Scheele and Chevreul much attention has been paid to glycerin and its compounds, and it is now universally agreed that glycerin is a trihydric or triatomic alcohol (see ALCOHOL), having the formula CH(OH), that is, containing the radicle C.H in combination with three OH groups. Hence glycerol bears the same relation to ordinary ethyl alcohol as orthophosphoric acid bears to nitric acid. And just as tribasic phosphoric acid forms three distinct classes of salts with three different proportions of the same base, so does glycerol form three distinct classes of esters: monoglycerides, diglycerides and triglycerides, and that it forms an acid and an oxide, and various substitution compounds and esters, of which latter class the fats (q.v.) are the most important members, and are distinguished by the name of “glycerides.”

Glycerin does not exist as such in the fats and fatty oils, but is formed by the assimilation of three molecules of water. However, glycerin does occur in nature in the uncombined form, notably as a constituent of palm-oil, and it is also a product of the alcoholic fermentation of sugar, and is therefore a normal constituent of beer, wine, etc., 100 parts of sugar yielding in fermentation 3.5 parts of glycerin. On the large scale, however, glycerin is prepared by the decomposition of fats. In commerce, five varieties of crude glycerin are recognized: (1) crude saponification glycerin; (2) crude distillation glycerin; (3) Twitchell crude glycerin; (4) fermentation glycerin; (5) soap lye glycerin. The purest form results from the saponification of fats with lime in

open vessels: that from soap lye processes may be equally pure if from a good class of fats. The other three sorts contain characteristic organic impurities which are not eliminated by the best known refining processes. The largest output is the soap lye grade.

In soap making the fat is decomposed by heating with an alkali, the soap which is formed by the combination of the alkali with the organic acid of the fat remaining in solution until it is precipitated by the addition of common salt. The fluid that remains after the soap has been so precipitated contains the liberated glycerin, which can be separated by distilling in a partially exhausted boiler, the glycerin passing over with the water vapor, from which it may be subsequently separated by reevaporation in a vacuum. In its commercial form it contains from 80 to 86 per cent of pure glycerin, 10 per cent of salts and 4 to 10 per cent of water.

Crude distillation glycerin is obtained in large quantities as a by-product in the manufacture of so-called "stearin" candles. In this case the fat is not saponified by an alkali, but beef fat, or some other fat that is rich in stearin, is acted upon by superheated steam, by which the stearin, or stearate of glycerin, is resolved into free stearic acid and free glycerin. Fat undergoes a similar transformation when treated with a mineral acid; but this method of producing glycerin has the disadvantage that the mineral acid is likely to combine to a certain extent, either with the glycerin, or with the liberated fatty acid, necessitating a subsequent treatment for its removal.

Glycerin is refined by distillation of the crude, and, if for dietetic or pharmaceutical purposes, is redistilled. The finest grade is triple distilled. Pure glycerin is a colorless, odorless, syrupy liquid, with an oily feel and an intensely sweet taste, and a specific gravity of about 1.27. It is insoluble in ether, but it mixes in all proportions with water and with alcohol. It has a considerable affinity for water, and absorbs moisture from the air quite readily to the extent of 50 per cent of its weight. It boils at about 600° F., but with partial decomposition. Under reduced pressures it boils at lower temperatures. At a pressure of 12.5 millimetres of mercury, for example, it boils at 356° F., and may be distilled without change. By subjecting pure glycerin to a temperature of 15° to 20° F., it will solidify in rhombic crystals, which melt at 68°. A large quantity of glycerin at 32° may be solidified by the introduction of a few glycerin crystals. Glycerin burns with an almost colorless flame, and dissolves many organic bodies that are insoluble in water. It also dissolves iodine, and many of the metallic oxides.

The solvent properties of glycerin render it valuable in pharmacy, and it is added to baker's cake in small quantities to keep it moist. Large quantities are used in the manufacture of toilet soaps, creams and washes, as a preservative medium, and in gas meters and other mechanical appliances in which a liquid is needed which will not readily freeze nor evaporate, but the largest part of the production is made into dynamite, blasting gelatine and smokeless powders.

GLYCIN, gli'sin. See GLYCOCOLL.

GLYCOCHOLIC (gli-ko-kōl'ik) ACID, an organic acid, whose sodium salt is one of the chief constituents of the bile of certain of the vertebrates. It may be most conveniently prepared by the following method: A drop of hydrochloric acid is added to fresh bile, generally of the ox, and the mixture is shaken and filtered. The filtrate is shaken with hydrochloric acid and ether and allowed to stand until the glycocholic acid separates in the form of a bulky mass of colorless needle-like crystals. These are collected upon a filter, washed with water containing hydrochloric acid and ether, and finally purified by recrystallization. Glycocholic acid is slightly sweet and bitter in its aqueous solution. It is readily soluble in alcohol, but dissolves sparingly in water, ether and cther solvents. It forms numerous salts, known as glycocholates, which are all soluble in alcohol. Those of the alkalis are very sweet, and are freely soluble in water, and yield lathers, like soap. Glycocholic acid is an amidoacid and has the formula C2H4NO, and when heated with potash it is resolved into cholic acid (CHO) and glycocoll (C2H.NO2), apparently according to the equation CH.NO. +H2OCHOS + C2H5NO2.

GLYCOCOLL, glikō-kõl, GLYCIN, GLYCOCIN, AMINO-ACETIC ACID, or GELATIN SUGAR, a singular chemical substance obtained by heating glycocholic acid (q.v.) with an alkali, or by the decomposition by long-continued boiling of gelatin, glue or gelatinous tissues, with sulphuric acid, or with potash or baryta. When perfectly pure it crystallizes in tabular, monoclinic crystals which darken at 430° F. and melt at 450° with the evolution of gas, but slight quantities of certain impurities induce remarkable changes in its crystalline form. It is insoluble in alcohol and in ether, but is sparingly soluble in water, its solution having a sweet taste. It is the chief amino-acid in the sugar-cane. According to its mode of formation from glue, glycocoll is. a sugar, the glue acting the part of a glucoside; but it resembles an acid (although it is neutral to litmus paper) inasmuch as it combines with metallic oxides to form salts. It does not form salts with the metals of the alkalis, and probably not with those of the alkaline earths. In combining with acids, glycocoll acts as a base, forming definite salts such as the nitrate, acetate, oxalate, sulphate and hydrochloride. In these compounds the glycocoll has strongly basic properties, and, indeed, it is usually described as a base. The chemical formula of glycocoll is CH.NO1; or CH2(NH2).COOH. Under the name "glycin" it is used as a photographic developer in place of pyrogallol.

GLYCOGEN, gli'ko-jen (CH10O5), was discovered in 1857 by Bernard and was given the name "animal starch." It belongs to that class of the carbohydrates called the polysaccharides; these are convertible into simple carbohydrates when hydrolysed. Glycogen is the reserve carbohydrate of the animal organism in which it appears to take the place of starch, and it is a normal constituent of all developing cells. It is found in the livers of most animals to the amount of 10 per cent and to some extent in the muscles and other parts of fœtal animals. It is formed by the action of a ferment on starches, transforming them into

sugars which undergo some alteration, becoming less soluble, and are then deposited in the liver and the muscular tissue. This storing of glycogen takes place in times of liberal feeding, but it disappears rapidly from the muscles in times of exertion. Glycogen is prepared from finely minced fresh liver, which is thrown into boiling water acidified with acetic acid. The proteins which coagulate are filtered out, and the remaining proteins precipitated from the filtrate with trichloracetic acid. From the remaining filtrate the glycogen is precipitated by adding alcohol. It is purified by resolution and reprecipitating with alcohol. It is obtained as an amorphous, snow white powder, yielding an opalescent solution with cold water. It does not ferment, nor does it reduce Fehling's solution, and it is not affected by boiling concentrated solutions of the alkalis. Acids hydrolyse it eventually to dextrose, but it passes through the phases of dextrins and maltose. Diastase also converts it to dextrins and maltose. The chief interest attaches to the physiological function of this substance, and the divergent views taken with regard to it by different writers. Thus it is said to be the substance in the liver mainly concerned in the conversion of starch into sugar. Other physiologists affirm that no such transformation takes place, there being no proof of the increase of sugar after the action of the liver; so that at the present time its exact functions are obscure. It has been suggested that the sugars that are taken into the system with the food are stored up in the liver in the form of glycogen, to be drawn upon subsequently, according to the needs of the system. In cases of diabetes glycogen is found in much larger quantities than usual, and in cases of starvation it is almost wholly absent. It is contained in the white blood corpuscles in very small amount. It is found in oysters to the extent of 3 per cent. It is found also in the cells of certain fungi, and at times in yeast where it may be very abundant, and then quickly disappear.

GLYCOL, or ETHYLENE ALCOHOL, the most important of the dihydric alcohols (see ALCOHOL and FATTY COMPOUNDS) may be regarded as derived from the hydrocarbon ethane, CH, by the substitution of two molecules of hydroxyl (OH) for two molecules of hydrogen, It therefore has the formula C.H.(OH) 2. Glycol may be prepared by acting upon ethylene dibromide, C2H.Br, by potassium carbonate, K.CO3. The reaction is C2H,Br2+ K2CO, + H2O=C2H1(OH), +2KBr + CO2. Glycol is a colorless, odorless liquid, having a specific gravity of about 1.12, and a sweetish taste. It boils at about 388° F., and solidifies at 11° F. It mixes in all proportions with water and alcohol, and is used to some extent as a solvent. A great many compounds have been derived from glycol, but they are not of general interest. The word "glycol" is also used as a generic name for all the dihydric alcohols.

GLYCOLLIC (gli-kŏl'îk) ACID, or OXYACETIC ACID, an organic acid having the formula HO.CH2COOH, whose potassium salt (that is, potassium glycollate) exists in the grease obtained from sheep's wool, in the juice of unripe grapes and as the principal acid in the juice of the sugar-cane. It is also found in the

lime precipitate after treatment of the juice of the sugar beet. It may be prepared by heating a mixture of glycerin, water, calcium hydrate and precipitated silver oxide for four hours, after which the fluid is filtered, saturated with carbon dioxide, boiled, filtered again and finally evaporated until calcium glycollate crystallizes out. The calcium glycollate is next decomposed by oxalic acid, and the filtered solution is neutralized with carbonate of lead. Upon evaporation, well-developed crystals of lead glycollate separate out; and a solution of these, when treated with the proper amount of sulphuric acid, yields free glycollic acid. By evaporation in a vacuum over concentrated sulphuric acid, and subsequent recrystallization from solution in anhydrous ether, the acid may be obtained in a very pure form. It is freely soluble in water, in alcohol, in ether and in acetone. Concentrated nitric acid oxidizes it to oxalic acid; and when distilled with excess of quicklime it decomposes with liberation of methane and hydrogen. Glycollic acid forms an extensive series of salts called glycollates, those of the alkalis being deliquescent, and it also yields numerous esters and other organic derivatives.

GLYCOSURIA, the presence of glucose in the urine. See DIABETES MELLITUS.

or

GLYCYRRHIZIN, glis-i-ri'zin, LIQUORICE SUGAR, an organic substance, the calcium and potassium salts of the tribasic glycyrrhizic acid, which occurs in liquorice root (Radix Glycyrrhiza) to the extent of 8 per cent, together with starch, malic acid and various other matters. In the juice of the bitter Anatolian liquorice the proportion ranges from 17 per cent as high as 25 per cent. It may be prepared by extracting the dried and pulverized liquorice root with boiling water containing a small quantity of milk of lime, and precipitating the concentrated extract with cold acetic acid. The gelatinous precipitate is purified by dissolving it in 50 per cent alcohol, filtering through charcoal, and finally evaporating at 212° F. When dry, glycyrrhizin is an amorphous solid, which swells up in cold water but does not dissolve. It is only slightly soluble in alcohol or ether, but dissolves in hot water, and also in boiling glacial acetic acid. It does not reduce Fehling's solution, nor the ammonical silver solution, but has been regarded as a glucoside. Although boiling with dilute acids decomposes it, it does not appear that any glucose or other sugar is formed, the chief products of the decomposition being parasaccharic acid and a brownish resin called glycyrrhetin.

GLYN, Elinor, English novelist: youngest daughter of Douglas Sutherland of Toronto, Ontario. In 1892 she married Clayton Glyn, J. P., (d. 1915). Her publications are The Visits of Elizabeth' (1900); The Reflection of Ambrosine (1902); The Damsel and the Sage' (1903); The Vicissitudes of Evangeline' (1905); Beyond the Rocks (1906); Three Weeks' (1907); The Sayings of Grandmama' (1908); Elizabeth Visits America? (1909); His Hour (1910); The Reason Why' (1911); (Halcyone' (1912); The Contrast, and Other Stories' (1913); The Sequence' (1913); 'Letters to Caroline (1914); Three Things' (1915); 'The Career of Catherine Bush' (1917).

GLYNN, Martin H., American politician and editor: b. Kinderhook, N. Y., 27 Sept. 1871. He was graduated at the head of his class at Saint John's College, Fordham, N. Y., in 1894, and four years later received the degree of A.M. from this institution. Since 1895 he has been managing editor of the Albany TimesUnion and in 1897 was admitted to the bar. He represented the 20th New York District in the 56th Congress, 1899-1901; was vice-president of the United States Commission at the Louisiana Purchase Exposition, Saint Louis, in 1904, and in 1906-08 was comptroller of New York State. In November 1912 he was elected lieutenant-governor of New York and on 14 Aug. 1913 assumed the office of governor, after impeachment proceedings had been instituted against William Sulzer. From 18 Oct. 1913 he was in full possession of the office, when Governor Sulzer was removed by Court of Impeachment. Mr. Glynn's term as governor expired 31 Dec. 1914. In 1914 he was nominated by the Democrats for governor, but was defeated by Charles S. Whitman.

GLYOXALIC ACID. See GLYOXYLIC

ACID.

GLYOXALINE, a substance having the chemical formula C.H.N2, and prepared by acting slowly upon cold glyoxal with strong ammonia in slight excess. Glycosine is thrown down as a brown precipitate, and the filtrate, which contains glyoxaline, is boiled with milk of lime (to expel the ammonia), after which it is evaporated to a syrupy consistency, treated with absolute alcohol to separate the mineral salts, and filtered, and the residue subjected to heavy pressure to gain all of the filtrate. The liquid so obtained is distilled, yielding pure glyoxaline in a crystalline mass of dazzling whiteness. Glyoxaline melts at 192° F., and boils at 491° F. It is freely soluble in water, alcohol and ether, and has an alkaline reaction. It acts as a base and forms salt. It is also the starting point for a series of organic compounds of analogous composition called glyoxalines. They are amidines in which two hydrogen atoms have been replaced, by the dyad group, CR'CR'. They are formed by the condensation of compounds containing the dicarbonyl group - CO.CO with aldehydes and ammonia jointly.

GLYOXYLIC or GLYOXALIC ACID, an organic acid having the formula H.CO.COOH, and existing in unripe apples, grapes, plums, currants and others, and in rhubarb and young beets. It may be prepared (along with glyoxal) by oxidizing alcohol, glycol or glycerol with nitric acid. It is a thick syrupy liquid having a specific gravity of about 1.3, and when allowed to stand long over concentrated sulphuric acid it crystallizes in rhombic prisms con-. taining water. Glyoxylic acid is very soluble in water, and can be distilled in a current of steam. It is a monobasic acid, forming crystalline salts called glyoxylates. By oxidizing agents it is converted into oxalic acid; by nascent hydrogen it is reduced to glycollic acid. It has also the properties of an aldehyde, reducing ammonical solutions of silver salts, forming a metallic mirror; also unites with alkaline bisulphites. It acts as a hydrolizing agent toward cane-sugar and starch, and pre

vents the fermentation of products thus formed, as it destroys the activity of yeast. Glyoxylic acid, when boiled with excess of lime water, yields calcium glycollate and calcium oxalate.

GLYPTICS, the art of engraving on gems and precious stones. It is generally done with diamond-pointed instruments, or instruments of exceeding hardness such as stellite.

GLYPTODONT, an armored edentate mammal of the extinct family glyptodontidæ, which developed mainly in South America during the Tertiary Period. Several genera__and many species have been described from Patagonia, the Argentine pampas, Peru, etc., and northward to the southern United States, associated with the great ground-sloths. These glyptodonts were allies of the armadilloes, and some of the more ancient species of the pampean region were very armadillo-like. As time advanced, however, the race developed into huge and grotesque species, the larger ones reaching a total length, including the tail, of 12 or 14 feet, and standing five feet high. Their general appearance must have been that of gigantic, high-backed, long-tailed tortoises; their squarish heads were turtle-like in shape; and their movements must have been slow and heavy, for these animals were massively armored against the big and savage beasts of their time. The top of the head was protected by a bony casque. The body and much of the limbs were enclosed in an immense domed carapace, which almost reached the ground at the sides. "It was composed of very thick polygonal plates of bone (no doubt covered externally with horny plates) immovably fixed together by their rough edges, and ornamented with an elaborate pattern of sculpture which varied with the genus." The tail, often exceeding the body in length, was enclosed in a defensive sheath of the same nature, and constituted an extraordinary and powerful weapon of defense. In Glyptodon it was made up of a series of overlapping rings, each ring double and bristling with sharp spikes. In Sclerocalyptus there were several rings around the root of the tail, diminishing posteriorly, and then blending into a long, smooth, somewhat flattened tube of bone, blunt at the tip. In Panocthus this tube carried a few heavy, horn-like spikes; and in Dædicurus the very long tube "had its free end greatly expanded and thickened into a huge, club-shaped mass, on the top and sides of which were fixed long and sharp horns." The skeleton was of the armadillo type, but modified and strengthened, especially in the spine and legs, to enable it to bear the great weight of the carapace; and the hind legs were much longer than the fore legs, giving the hips a humped appearance. The broad feet had five toes in each pair, and in some species these were armed with powerful claws to enable them to dig roots and tubers. All the glyptodonts were plant-feeders, and entirely harmless. "When attacked by the saber-toothed tigers (Smilodon) or the great bears (Arctotherium) they needed only to squat down, bringing the edges of the carapace to the ground, and draw in the head," says Scott, "to be perfectly protected, while a sweep of the spiny and club-like or horny tail would have been fatal to everything in its path." The Texan species (Gomphotherium) was smaller, had less armament and a shorter