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things, inaccessible places and immense trines B. Yes; with less trouble, confusion and and spaces.

expense than a knight of the shire is chosen A. What now is the liberty you mean? in ary county of England.

B. That any man may worship God other- A. But would not an assembly interfere wise than as the aforementioned national with the present constitutions of ParliaChurch appoints, and my profess opinions ment ? in spiritual matters other than those deter- B. No. It seems to me to be a bare mined by the said Church, provided that council of quite another nature, without such seeker of liberty do solemnly protest any legislative power at all, only to quiet before God that he verily believes his par- the people concerning invisible and purely ticular opinions to be true, and that the spiritual matters. same, with the manner of worship he de- A. Is there no other way to regulate and sireth, is necessary for the peace and wel- perpetuate the liberty of conscience which fare of his soul, and that in all other matters you have described ? he will submit to the laws of his sovereign. B. I cannot think of any at present, but A. What do you mean by liberty ? for you will consider it further.

. said there was no liberty in believing.

SIR WILLIAM Petty. B. I mean impunity—that is, no man shall be punished, in life, limb, liberty or estate, for dissenting from the national Church, leaving

A SERENADE. him to God to be punished for what is sinful therein, reserving still to the sovereign a right Lo ,

LOOK

OOK out upon the stars, my love, punishing, or suppressing even, the same And shame them with thine eyes, opinions, if inconsistent with the public peace On which than on the lights above and welfare of the people, of which the sov- There hang more destinies. ereign is to be judge.

Night's beauty is the harmony A. How inay this liberty be perpetuated Of blending shades and light; under all forms and successions of govern- Then, lady, up! Look out, and be ment and changes of Parliament, and what A sister to the night. oaths to be taken now or hereafter ?

B. It seems to me it can only be perpet- Sleep not! Thine image wakes for aye uated by the vox populi, or the voice of all

Within my watching breast. the people who have souls to save, who are Sleep not! From her soft sleep should fly able to bear arms and are of years of discre- Who robs all hearts of rest. tion-suppose twenty-one years old. For in Nay, lady ; from thy slumbers break,

these doth visibly, naturally and perpetually And make this darkness

gay lie the infallible or irresistible power concern- With looks whose brightness well mighing these matters of the soul.

make A. Can' all these people be represented Of darker nights a day. practically and conveniently ?

EDWARD C. PINKNEY,

THE STRUGGLE FOR EXISTENCE.

somne

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GEOMETRICAL RATIO OF IN

in twenty-five years, and at this rate in less CREASE

than a thousand years there would literally STRUGGLE for existence not be standing-room for bis progeny. Lininevitably follows from the næus has calculated that if an annual plant high rate at which all or- produced only two seeds—and there is no ganic beings tend to increase. plant so unproductive as this—and their seedEvery being which during its lings next year produced two, and so on, then natural lifetime produces sev- in twenty years there would be a million eral eggs or seeds must suf- plants. The elephant is reckoned the slowest fer destruction during some breeder of all known animals, and I have period of its life, and during taken some pains to estimate its probable

season or occasional minimum rate of natural increase. It will be year, otherwise, on the prin- safest to assume that it begins breeding when

,

ciple of geometrical increase, thirty years old and goes on breeding till its numbers would quickly become so inor- ninety years old, bringing forth six young

in dinately great that no country could support the interval, and surviving till one hundred the product. Hence, as more individuals are years old; if this be so, after a period of from produced than can possibly survive, there must seven hundred and forty to seven hundred in every case be a struggle for existence and fisty years there would be nearly nineteen -either one individual with another of the million elephants alive, descended from the same species, or with the individuals of dis- first pair. tinct species, or with the physical conditions But we have better evidence on this subof life. It is the doctrine of Malthus applied ject than mere theoretical calculationswith manifold force to the whole animal and namely, the numerous recorded cases of the vegetable kingdoms, for in this case there can astonishingly rapid increase of various anibe no artificial increase of food and no pru- mals in a state of nature, when circumstances dential restraint from marriage. Although have been favorable to them during two or some species may be now increasing more or three following seasons. Still more striking less rapidly in numbers, all cannot do so, for is the evidence from our domestic animals of the world would not hold them.

many

kinds which have run wild in several There is no exception to the rule that every parts of the world; if the statements of the

1 organic being naturally increases at so high a rate of increase of slow-breeding cattle and rate that if not destroyed the earth would horses in South America, and latterly in Aussoon be covered by the progeny of a single tralia, had not been well authenticated, they pair. Even slow-breeding man has doubled would have been incredible. So it is with

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plants; cases could be given of introduced food, and that in a state of nature an equal plants which have become common through- number would have somehow to be disposed of. out whole islands in a period of less than ten · The only difference between organisins years. Several of the plants, such as the car- which annually produce eggs or seeds by the doon and a tall thistle, which are now the thousand and those which produce extremely commonest over the wide plains of La Plata, few is that the slow-breeders would require a clothing square leagues of surface almost to few more years to people, under favorable the exclusion of every other plant, have been conditions, a whole district, let it be ever so introduced from Europe, and there are plants large. The condor lays a couple of eggs and which now range in India, as I hear from Dr. the ostrich a score, and yet in the same counFalconer, from Cape Comorin to the Him- try the condor may be the more numerons of alaya, which have been imported froro Amer- the two; the Fulmar petrel lays but one egg, ica since its discovery. In such cases—and yet it is believed to be the most numerous endless others could be given-no one sup- bird in the world. One fly deposits hundreds poses that the fertility of the animals or plants of eggs, and another, like the hippobosca, has been suddenly and teinporarily increased in single one, but this difference does not deterany sensible degree. The obvious explanation mine how many individuals of the two species is that the conditions of life have been highly can be supported in a district. A large numfavorable, and that there has consequently ber of eggs is of some importance to those been less destruction of the old and young, species which depend on a fluctuating amount and that nearly all the young have been en- of food, for it allows them rapidly to increase abled to breed. Their geometrical ratio of in number.

in number. But the real importance of a increase, the result of which never fails to be large number of eggs or seeds is to make up surprising, simply explains their extraordi- for much destruction at some period of life, rarily rapid increase and wide diffusion in their and this period in the great majority of cases new homes.

is an early one. If an animal can in any way In a state of nature almost every full-grown protect its own eggs or young, a small numplant annually produces seed, and amongst ber may be produced and yet the average animals there are very ew which do not an- stock be fully kept up; but if many eggs or nually pair; hence we may confidently assert young are destroyed, many must be produced, that all plants and animals are tending to in- or the species will become extinct. It would crease at a geometrical ratio, that all would suffice to keep up the full number of a tree rapidly stock every station in which they which lived on an average for a thousand could anyhow exist, and that this geometrical years if a single seed were produced once in tendency to increase must be checked by de- a thousand years, supposing that this seed

a struction at some period of life. Our famili- were never destroyed and could be ensured arity with the larger domestic animals tends, I to germinate in a fitting place. So that, in think, to mislead us : we see no great destruc- all cases, the average number of any animal tion falling on them, but we do not keep in mind or plant depends only indirectly on the numthat thousands are annually slaughtered for ber of its eggs or seeds.

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In looking at Nature it is most necessary and insects. If turf which has long been to keep the foregoing considerations always mown-and the case would be the same with in inind--never to forget that every single turf closely browsed by quadrupeds--be let organic being may be said to be striving to to grow, the more vigorous plants gradually the utmost to increase in numbers, that each kill the less vigorous, though fully-grown lives by a struggle at some period of its life, plants: thus, out of twenty species grown on that heavy destruction inevitably falls either a little plot of mown turf (three feet by four) on the young or old during each generation or nine species perished from the other species at recurrent intervals. Lighten any check, being allowed to grow up freely. mitigate the destruction ever so little, and the The amount of food for each species of number of the species will almost instantane- course gives the extreme limit to which each ously increase to any amount.

can increase, but very frequently it is not the

obtaining food, but the serving as prey to NATURE OF THE CHECKS TO INCREASE. other animals, which determines the average

The causes which check the natural tend- numbers of a species; thus there seems to be ency of each species to increase are most little doubt that the stock of partridges, obscure. Look at the most vigorous species; grouse and hares on any large estate depends by as much as it swarms in numbers, by so

so chiefly on the destruction of vermin. If not much will it tend to increase still further. one head of game were shot during the next We know not exactly what the checks are twenty years in England, and, at the same even in a single instance. Nor will this sur- time, if no rermin were destroyed, there prise any one who reflects how ignorant we would, in all probability, be less game

than are on this head eren in regard to mankind, at present, although hundreds of thousands although so incomparably better known than of game-animals are now annually shot. On any other animal. Eggs or very young ani- the other hand, in some cases, as with the mals seem generally to suffer most, but this elephant, none are destroyed by beasts of is not invariably the case. With plants there prey; for even the tiger in India most rarely is a vast destruction of seeds, but from some dares to attack a young elephant protected observations which I have made it appears by its dam. that the seedlings suffer most from germinat- Climate plays an important part in detering in ground alreally thickly stocked with mining the average numbers of a species, and other plants. Seedlinys, also, are destroyed periodical seasons of extreme cold or drought in vast numbers by various enemies. For seem to be the most effective of all checks. instance, on a piece of ground three feet long I estimated (chiefly from the greatly-reduced and two wide, dug and cleared, and where numbers of nests in the spring) that the winthere could be no choking from other plants, ter of 1854–5 destroyed four-fifths of the I marked all the seedlings of our native weeds birds in my own grounds; and this is a as they came up, and out of three hundred tremendous destruction, when we remember and fifty-seven no less than two hundred and that ten per cent. is an extraordinarily severe ninety-five were destroyed, chiefly by slugs mortality from epidemics with man. The action of climate seems at first sight to be or snow-capped summits or absolute deserts, quite independent of the struggle for exist- the struggle for life is almost exclusively with ence, but, in so far as climate chiefly acts in the elements. reducing food, it brings on the most severe That climate acts in main part indirectly struggle between the individuals, whether of by favoring other species we clearly see in the same or of distinct species, which subsist the prodigious number of plants which in our on the same kind of food. Even when cli- gardlens can perfectly well endure our climate, mate—for instance, extreme cold—acts di- but which never become naturalized, for they rectly, it will be the least vigorous individuals cannot compete with our native plants nor or those which have got least food through resist destruction by our native animals. the advancing winter which will suffer most. When a species, owing to highly favorable When we travel from south to north or from circumstances, increases inordinately in numa damp region to a dry, we invariably see bers in a small tract, epidemies—at least, this some species gradually getting rarer and rarer, seems generally to occur with our gameand finally disappearing, and, the change of animals—often ensue; and here we have a climate being conspicuous, we are tempted to limiting check independent of the struggle for attribute the whole effect to its direct action. life. But even some of these so-called epi

. But this is a false view: we forget that each demies appear to be due to parasitic worms species, even where it most abounds, is con- which have from some cause-possibly, in stantly suffering enormous destruction at some part, through facility of diffusion amongst the period of its life from enemies or from com- crowded animals—been disproportionally fapetitors for the same place and food; and if vored; and here comes in a sort of struggle these enemies or competitors be in the least between the parasite and its prey. degree favored by any slight change of cli- On the other hand, in many cases a large mate, they will increase in numbers, and, as stock of individuals of the same species, relaeach area is already fully stocked with in- tively to the numbers of its enemies, is absohabitants, the other species must decrease. lutely necessary for its preservation. Thus When we travel southward and see a species we can easily raise plenty of corn and rapedecreasing in numbers, we may feel sure that seed, etc., in our fields, because the seeds are the cause lies quite as much in other species in great excess compared with the number of being favored as in this one being hurt. So 'birds which feed on them; nor can the birds, it is when we travel northward, but in a some though having a superabundance of food at what lesser degree, for the number of species ! this one season, increase in number proporof all kinds, and therefore of competitors, de- ; tionally to the supply of seed, as their numcreases northward; hence, in going northward bers are checked during winter; but any one or in ascending a mountain, we far oftenerwio has tried knows how troublesome it is to meet with stunted forms, due to the directly get seed from a few wheat or other such plants injurious action of climate, than we do in in a garden : I have in this case lost every proceeding south ward or in descending a single seed. This view of the necessity of a mountain. When we reach the Arctic regions large stock of the same species for its preser

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