tance be confidered as the effect of enthusiasm; a whole day may be spent here without having time to view every thing that is worthy of being feen. After having spent in thefe caverns twelve hours and a half, we left them without having fuffered any difafter except extreme fatigue. The air is moift without being noxious; it is even friendly to weak lungs. When we left this place of enchantment, and emerged into day, we thought our felves newly awaked out of a dream which we were forry had ended. There may be in the bowels of the earth other grottoes as beautiful as this; but my perfuafion, that none of them can excell it, is the only motive that has prompted me to publish this defcription, for the exactnefs and aus thenticity of which I fhall be anfwerable. Account of the Infects called Aphides, and Remarks on the Natural History of the Bee. By George Adams. HE habits of the Pucerons are fo very fingular, that I cannot pass them over in filence; the more fo, as they are a very curious object for the microscope. They are called by various names, the proper one is aphis; that which they are most known by is puceron, though they are fometimes called vine-fretters and plantlice. They belong to the hemiptera order. The roftrum is inflected, the antennæ are longer than the thorax, fome have four erect wings, others have none at all: towards the end of the belly there are two tubes, from which is ejected that most delicate juice called honey-dew. and this you may purfue through many generations. Mr Bonnet had repeated experi ments of this kind, as far as the fixth generation, which all uniformly pres fented the obferver with fruitful vir« gins, when he was engaged in a feries of new and tedious experiments, from a fufpicion imparted by Mr Trembley in a letter to him, who thus expreffes himself: "I have formed the defign "of rearing feveral generations of foli "tary pucerons, in order to fee if they "would all equally bring forth young. "In cafes fo remote from ufual cir "cumftances, it is allowed to try all "forts of means; and I argued with The aphides are a very numerous "myself, who knows but that one genus. Linnæus has enumerated thir-" copulation might ferve for several ty-three different fpecies, whofe trivial names are taken from the plant which they inhabit, though it is probable the number is much larger, as the fame plant is often found to fupport two or three different forts of aphides. An aphis, or puceron, brought up in the most perfect folitude from the very moment of its birth, in a few days will be found in the midst of a numerous family repeat the experiment on one of the individuals of this family, and you will find this fecond generation will multiply like its parent, "generations?" This "who knows" perfuaded Mr Bonnet that he had not fufficiently pursued his inveftigations. He therefore now reared to the tenth generation his folitary aphides, having the patience to keep an exact account of the days and hours of the birth of each generation. He then discovered both males and females among them, whofe amours were not in the leaft equivocal; the males are produced only in the tenth generation, and are but few in number; that these foon arriving at their full growth, co Effays on the Microfcope; lately published. pulate pulate with the females, and that the virtue of this copulation ferves for ten fucceffive generations; that all thefe generations, except the firft, from fecundated eggs, are produced viviparous, and all the individuals are females, except those of the last generation, among whom fome males appear to lay the foundation of a fresh series. In order to give a further infight into the nature of thefe infects, I shall infert an extract of a defcription of the different generations of them by Dr Richardfon, as published in the Philofophical Tranfactions, vol. Ixi. "The great variety of fpecies which occur in the infects now under confideration, may make an inquiry into their particular natures feem not a little perplexing; but by reducing them under their proper genus, the difficulty is confiderably diminished. We may reasonably fuppofe all the infects, com prehended under any diftinct genus, to partake of one general nature; and by diligently examining any particular fpecies, may thence gain fome infight into the nature of all the ref. With this view Dr Richardson chofe out of the various forts of aphides the largest of those found on the rofe-tree, not only as its fize makes it more confpicuous, but as there are few others of fo long a duration. This fort appears early in the Spring, and continues late in the Autumn; while feveral are limited to a much fhorter term, in conformity to the different trees and plants from whence they draw their nourish ment. 1. If at the beginning of February the weather happens to be fo warm as to make the buds of the rofe-tree fwell and appear green, fmall aphides are frequently to be found on them, tho' not larger than the young ones in Summer, when firft produced. It will be found, that thofe aphides which appear only in Spring, proceed from fmall black oval eggs, which were depofited on the last year's foot; though when it happens that the infect makes too early an appearance, the greater part fuffer from the fharp weather that u fually fucceeds; by which means, the rofe-trees are fome years in a manner freed from them. The fame kind of animal is then at one time of the year viviparous, and at another oviparous. Those aphides which ftand the fes verity of the weather feldom come to their full growth before the month of April, at which time they ufually begin to breed, after twice calling off their exuvia, or outward covering. It appears that they are all females, which produce each of them a numerous pro geny, and that without having intercourfe with any male infect; they are viviparous, and what is equally fingu lar, the young ones all come into the world backwards. When they firft come from the parent, they are enveloped by a thin inembrane, having in this fituation the appearance of an oval egg; thefe egg-like appearances adhere by one extremity to the mother, while the young ones contained in them extend the other, by that means gradually drawing the ruptured membrane over the head and body to the hind feet. During this operation, and for fome time after, the fore part of the head adheres, by means of fomething glu tinous, to the vent of the parent. Being thus fufpended in the air, it foon frees itfelf from the membrane in which it was confined; and after its limbs are a little strengthened, is fet down on fome tender fhoots, and left to provide for itself. In the Spring months there appear on the rofe-trees but two generations of aphides, including thofe which proceed immediately from the last year's eggs; the warmth of the Summer adds fo much to their fertility, that no lefs than five generations fucceed one another in the interval One is produced in May, which cafts off its covering while the months of June and July each fupply two more, which caft off their coverings three or four times, according the feafon. This frequent change of their outward coat is the more extraordinary, because it is repeated more often when the infects come the fooneft to their growth, which fometimes happens in ten days, where warmth and plenty of nourishment confpired. according to the different warmth of two of which generally make their ap pearance in the month of Auguft, and the third before the middle of September. The two firft differ in no refpe&t from thofe which are found in Summer; but the third differs greatly from all the reft. Tho' all the aphides which have hitherto appeared were fes males, in this tenth generation feveral male infects are found, but not by any means fo numerous as the females. Early in the month of June, fome of the third generation which were produced about the middle of May, after cafting off their laft covering, difcover four ere& wings much longer than their bodies; and the fame is obfervable in all the fucceeding generations which are produced during the Summer months, but ftill without any diyerfity of fex; for fome time before the aphides come to their full growth, it is cafy to diftinguish which will have wings, by a remarkable fullnefs of the breaft, which in the others is hardly to be diftinguished from the body. When the last covering is rejected, the wings, which were before folded up in a very narrow compafs, are gradually extended in a very furprizing manner, till their dimenfions are at lat very confiderable. The increafe of thefe infects in the Summer time is fo very great, that by wounding and exhausting the tender fhoots they would frequently fupprefs all vegetation, had they not many enemies to refrain them. Notwithftanding these infects have a numerous tribe of enemies, they are not without friends, if thofe may be confidered as fuch, who are officious in their attends ance for the good things they expect to reap thereby. The ant and the bee are of this kind, collecting the honey in which the aphides abound, but with this difference, that the ants are conftant visitors, the bee only when flowers are scarce; the ants will fuck in the honey while the aphides are in the act of difcharging it; the bees only collect it from the leaves on which it bas fallen. . In the Autumn three more genesations of the aphides are produced, YOL. VII. No 39. The females have at firft the fame appearance with thofe of the former generations, but in a few days their colour changes from a green to a yellow, which is gradually converted into an orange before they come to their full growth; they differ alfo in another refpect from thofe which occur in Summer, for all thefe yellow females are without wings. The male infects are, however, ftill more remarkable, their outward appearance readily diftinguishing them from this and all other generations. When first, produced, they are not of a green colour like the reft, but of a reddifh brown, and have afterwards a dark line along the back; they come to their full growth in about three weeks, and then caft off their laft covering, the whole infect being after this of a bright yellow colour, the wings only excepted; but after this change to a deeper yellow, and in a very few hours to a dark brown, if we except the body, which is fomething lighter coloured, and has a reddish caft. The males no fooner come to maturity than they copulate with the females, who in day or two after their intercourfe with the males lay their eggs, generally near the buds. Where there are a num ber crowded together, they of course, interfere with each other, in which they will frequently depofit their eggs on other parts of the branches. It is highly probable that the aphides derive confiderable advantages by living in fociety; the reiterated punctures of a great number of them may attract a larger quantity of nutritiCc ous bus juices to that part of the tree, or plant, where they have taken up their abode. In the natural history of infects, new objects of furprize are continually rifing before the obferver: fingular as we have already fhewn is the production of the Puceron, that of the Bee will not be found to be lefs fo; and though this little republic has at all times gained univerfal esteem and admiration, though they have attracted the attention of the moft ingenious and laborious inquirers into nature, yet the mode of propagating their Species feems to have baffled the ingenuity of ages, and rendered their attempts to difcover it abortive; even the labours and fcrupulous attention of Swammerdam were unfuccefsful; though, while he was writing his treatife on bees, his daily labour began at fix in the morning, and from that hour till twelve he continued watching their operations, his head in a manner diffolving into fweat, under the irrefiftible ardour of the fun; and if he defifted at noon, it was only becaufe his eyes then became too weak, as well from the extraordinary afflux of light and the ufe of glaffes, to continue longer exercifed by fuch minute objects. He spent one month entirely in examining, defcribing, and repte fenting their inteftines; and many months on other parts: employing whole days in making obfervations, and whole nights in regiftering them, till at last he brought his treatise of bees to the wifhed-for perfection; a work which all the ages, from the Commencement of natural hiftory to our own times, have produced nothing to equal, nothing to compare with it. "Read it, fays the great Boerhaave, confider it, and then judge for yourReaumur, however, thought he had in some measure removed the veil, and explained their manner of generating he fuppofes the queen-bee to be the only female in the hive, and the mother of the next generation; that the drones are the males, by which fhe is fecundated: and that the work ing bees, or those that collect wax on the flowers, that knead it, and form from it the combs and cells, which they afterwards fill with honey, are of neither fex. The queen-bee is known by its fize, being generally much larger than the working-bee or the drone. . Mr Schirach, a German naturalift, affirms, that all the common bees are females in difguife, in which the organs that diftinguifh the fex, and particu larly the ovaria, are obliterated, or at leaft from their extreme minuteness have efcaped the obferver's eye; that every one of thofe bees, in the earlier period of its existence, is capable of becoming a queen bee, if the whole community fhould think it proper to nurfe it in a particular manner, and raife it to that rank: in fhort, that the queen bee lays only two kinds of eggs, thofe that are to produce the drones, and thofe from which the working bees are to proceed. Mr Schirach made his experiments not only in the early Spring months, but even as late as November. He cut off from an old hive a piece of the brood-comb, taking care that it contained worms which had been hatched about three days. He fixed this in an empty hive, together with a piece of honey-comb, for food to his bees, and then introduced a number of com mon bees into the hive. As foon as these found themselves deprived of their queen and their liberty, a dreadful uproar took place, which lafted for the fpace of twenty-four hours. On the ceffation of this tumult they betook themselves to work, firft proceeding to the conftruction of a royal cell, and then taking the proper methods for feeding and hatching the brood inclo fed with them; fometimes even on the fecond day the foundation of one or more royal cells were to be percei ved; the view of which furnished cer tain indications that they had elected one of the inclosed worms to the forereignty. The bees may now be left at liberty. The final refult of thefe experiments is, that the colony of working bees being thus fhut up with a morfel of brood-comb, not only hatch, but at the end of eighteen or twenty days produce from thence one or two queens, which have to all appearance proceeded from worms of the common fort, which appears to have been converted by them into a queen, merely because they wanted one. From experiments of the fame kind, varied and often repeated, Mr Shirach concludes that all the common working bees were originally of the female sex; but that if they are not fed, lodged, and brought up in a particular manner while they are in a larva ftate, their organs are not developed; and that it is to this circumftance attending the bringing up of the queen, that the extenfion of the female organs is effected, and the difference in her form and fize produced. Mr Debraw has carried the subject further, by difcovering the impregnation of the eggs by the males, and the difference of the fize among the drones or males; though indeed this laft circumftance was not unknown to Mefs. Maraldi and Reaumur. Mr Debraw watched the glafs hives with indefatigable attention, from the moment the bees, among which he took care there fhould be a large number of drones, were put into them, to the queen's laying her eggs, which gene rally happens the fourth or fifth day; he obferved, that on the first or fecond day (always before the third) from the time the eggs are placed in the cells, a great number of bees fastening themselves to one another hung down in the form of a curtain, from the top to the bottom of the hive; they had done the fame at the time the queen depofited her eggs, an operation which feems contrived on purpofe to conceal what is tranfacting: however, through fome parts of this veil he was enabled to fee fome of the bees inferting the pofterior part of their bodies each into a cell, and finking into, but continuing there only a little while. When they had retired, it was eafy to difcover a whitifh liquor left in the angle of the bafis of each cell, which contained an egg. In a day or two this liquor was abforbed into the embryo, which on the fourth day affumes its worm or larva state, to which the working becs bring a little honey for nourishment, during the firft eight or ten days after its birth. When the bees find the worm has attained its full growth, they leave off bringing it food, they know it has no more need of it; they have ftill, however, another fervice to pay it, in which they never fail, it is that of fhutting it up in its cell, where the larva is inclofed for eight or ten days: here a further change takes place ;"the larva, which was heretefore idle, now begins to work, and lines its cell with fine filk, while the working-bees inclose it exteriorly with a wax covering. The concealed larva then voids its excrement, quits its fkin, and affumes the pupa; at the end of fome days the young bee acquires fufficient ftrength to quit the flender covering of the pupa, tear the wax covering of its cell, and proceeds a perfect infect. To prove further that the eggs are fecundated by the males, and that their prefence is neceffary at the time of breeding, Mr Debraw made the following experiments. They confift in leaving in a hive the queen, with only the common or working bees, without any drones, to fee whether the eggs fhe laid would be prolific. To this end, he took a fwarm, and fhook all the bees into a tub of water, leaving them there till they were quite fenfelefs; by which means he could diftinguish the drones, without any danger of being ftung: he then reftored the queen and working-bees to their former ftate, by fpreading them on a brown paper in the fun; after Cc 2 th |