ANIMALCULE. 



113 



lowish on the upper part, and dusky blue on the 

 other. In all the varieties of colour, the three rows 

 of spots distinguish it, unless when the upper part is 

 black, and that is a distinction, as the harmless snake 

 is never darker than brown. It also has always bands 

 of dark spots across, while the other has none. 



ANIMALCULE is literally the diminutive of 

 the word animal, and as such signifies " a little living 

 creature," a sense which is abundantly vague ; but its 

 application is restricted to an exceedingly numerous 

 class of animals, which are, generally speaking, in- 

 visible to the naked eye, forming, as it were, a new 

 world, which has been revealed to human knowledge 

 by the microscope, and to which there appears to be 

 no limit, save in the powers of that instrument. As 

 these minute creatures are found only in liquids, in 

 which vegetable or animal matters have been par- 

 tially dissolved by infusion, they are sometimes 

 called Infusoria ; but the term is apt to mislead, as 

 an infusion can no more of itself produce an animal- 

 cule, than the water can of itself produce a fish, or 

 the air a bird, or than a house can produce a human 

 being. The infusion favours their development, just 

 as the development of larger animals is favoured by 

 certain states of the weather and other circumstances ; 

 but the analogy of all nature demands that the germ 

 of the animalcule should be there as well as that of 

 the elephant or the whale, otherwise it would be as 

 vain to look for the small animal as the large one. 

 This fundamental principle we must carry along with 

 us in every case of organised being, even though the 

 details of the organisation be too minute for our per- 

 ception, and the fact of its existence more an inference 

 from the function than a direct result of observation. 



And, upon this microscopic confine of our know- 

 ledge it behoves us to be very circumspect, inas- 

 much as the animal function is often as obscure as the 

 organisation ; so that it is only with the best instru- 

 ments, the most careful and patient observation, and 

 minds totally divested of all theory, or preconceived 

 nature of what we are to find, that we can arrive at 

 the truth. The grand law as to function is that in- 

 organic matter obeys only certain attractions and 

 repulsions, while that which is organised obeys new 

 laws in opposition to these. Under a powerful mi- 

 croscope, however, there is always doubt, unless we 

 can discern both organisation and function ; and 

 therefore this is not a department in which ordinary 

 popular observation can well extend the bounds of 

 knowledge. 



But it does not thence follow that the subject is not 

 one of popular use, for many of the most valuable 

 parts of our knowledge, can be extended in them- 

 selves and their connexion with each other only by 

 the few who are content to forego the common pur- 

 suits and pleasures of life, and toil and study with- 

 out associate and without sympathy, supported by 

 the sure hope that that which they are sowing in 

 silence and secret will grow up and enrich the 

 world with its fruits. 



In this way, microscopic labours in natural history, 

 and especially in the natural history of animalcules, 

 are of very great importance in a popular and practi- 

 cal sense. They show us that, if we follow it in the 

 direction of the minute, there is just as little limit to 

 nature as when, by the aid of the telescope, we fol- 

 low it to the vast. When we think of the myriads 

 of stars, myriad behind myriad deepening into space, 

 which a powerful telescope discloses in a very small 



NAT. HIST. VOL. I. 



portion of the heavens ; when we consider that all 

 these are certainly further apart from each other, and 

 the nearest more distant from us than the swiftest- 

 winged bird could fly in ten thousand years ; tjiat 

 each of them is, by the most rational analogy, a sun 

 surrounded by many worlds, all peopled with growth 

 and life ; that what the telescope thus reveals, is 

 limited by the imperfection of that instrument, so as 

 only to constitute the mere beginning ; and that, 

 though we could reach the most distant of those 

 stars as easily in the body as we can in thought, w(; 

 should not perceptibly change our place in the uni- 

 verse : when we think in this manner, we feel what 

 a wonderful thing creation is, and how unspeakably 

 beneficent it is in the great Creator of all things to 

 give such a system for our contemplation, and ac- 

 cording to our knowledge for our use. 



But even this view, grand and sublime as it is, is 

 not complete, until we take hold of the microscope, 

 and view the series the other way. Then we dis- 

 cover that the little globule of water that we can lift 

 on a pin's-point is a miniature of this giant univeise, 

 instinct with living creatures which no arithmetic 

 can count ; and that in them, organisation and life 

 are, according to their species, as perfect as they are 

 in the largest animals which walk the earth or spor 

 in the waters ; that the fluids of plants and animals 

 are full of life and its germs ; and that the eye can- 

 not so divide space, even by the aid of the instru- 

 ment, as to enable us to say of the smallest sensible 

 portion, "there is no living creature contained here." 

 But here again we are limited by the imperfection 

 of the instrument, and know not how much may lie 

 between what has been discovered and the final 

 bourn, at which organic life touches on the element- 

 ary particle. And when we glance our thoughts 

 along this wonderful series, the first thing that strikts 

 us is, that it is all equally perfect. Their functions 

 are as varied as their forms and magnitudes ; but 

 when we compare each with the circumstances in 

 which it is placed, we cannot say that one is relatively 

 stronger or weaker than another : the animalcule in 

 its drop of water is just as much "adapted and at 

 home" as the elephant in the jungle, or the sun 

 careering through measureless distance with all the 

 planets in his train. 



And it is further worthy of remark, that the law of 

 life from the whale to the animalcule is one law. This 

 unity and uniformity are established by the study of 

 this branch of the animal kingdom. They, like tie 

 larger animals, have their different degrees of organ- 

 isation ; and, in conformity with what was said of these 

 in the introduction to this work, the simpler the organ- 

 isation the more retentive are they of life. Besides, 

 in all cases where it is discernible, the germ can 

 endure more than the developed animalcule, and 

 there may be an initiatory point in its living in which 

 it is proof against all destroying causes. 



Some of the species of more simple organisation 

 can bear to be boiled in close vessels, and others can 

 bear a greater degree of cold than that at which 

 water freezes. In general, however, the freezing of 

 the water kills them ; and some of those of the more 

 complicated organisations cannot bear a tempera- 

 ture so high as that of the human body in ordinary 

 health. In the case of freezing and thawing, it is 

 not always easily ascertained whether it is the animals 

 themselves which are resuscitated, or merely the eggs 

 or other germs preserved and brought to maturity. 



