INTRODUCTION. 



19 



Differences of this kind, between organized beings, are what are termed varieties. 



There is no proof that all the differences which now distinguish organized beings are 

 such as may have been produced by circumstances. All that has been advanced upon 

 this subject is hypothetical : experience seems to show, on the contrary, that, in 

 the actual state of things, varieties are confined within rather narrow limits ; and, 

 so far as we can retrace antiquity, we perceive that these limits were the same as at 

 present. 



We are then obliged to admit of certain forms, which, since the origin of things, 

 have been perpetuated without exceeding these limits ; and all the beings appertaining 

 to one of these forms constitute what is termed a species. Varieties are accidental 

 subdivisions of species. 



Generation being the only means of ascertaining the limits to which varieties may 

 extend, species should be defined the reunion of individuals descended one from the 

 other, or from common parents, or from such as resemble them as closely as they 

 resemble each other ; but, although this definition is rigorous, it will be seen that its 

 application to particular individuals may be very difficult when the necessary experi- 

 ments have not been made.* 



To recapitulate, — absorption, assimilation, exhalation, developement, and generation, 

 are the functions common to all living beings ; birth and death, the universal limits of 

 their existence ; a porous, contractile tissue, containing within its laminae liquids or 

 gases in motion, the general essence of their structure ; substances almost all 

 susceptible of being converted into liquids or gases, and combinations capable of easy 

 transformation into one another, the basis of their chemical composition. Fixed 

 forms, and which are perpetuated by generation, distinguish their species, determine 

 the complication of the secondary functions proper to each of them, and assign to them 

 the office they have to fulfil in the grand scheme of the universe. These forms 

 neither produce nor change themselves ; the life supposes their existence ; it can exist 

 only in organizations already prepared ; and the most profound meditations, assisted 

 by the most delicate observations, can penetrate no further than the mystery of the 

 pre-existence of germs. 



DIVISION OF ORGANIZED BEINGS INTO ANIMALS AND VEGETABLES. 



Living or organized beings have been subdivided, from the earliest times, into ani- 

 mate bei/iys, or those possessing sense and motion, and inanimate beings, which enjoy 



• That insurmountable difficulties oppose the rigid determination of 

 species, and, consequently, render even the definition of the tirtn 

 Impossible, except in a very vague »nd loose manner, will readily 

 appear on consideration of some of the phenomena presented. 

 The prevalent idea is, that a ipeciet consists of the aggregate of 

 Individuals descended from one original parentage, which alone arc 

 supposed to be capable of producing offspring that are prolific inter 

 le ; and that when individuals, not of the same pristine derivation, 

 Interbreed, the hybrids are necessarily mulrt , which are cither quite 

 sterile, or at most can only propagate with individuals of nui 

 descent. But it so happens, that every possible gTadc of approst* 

 ;i is manifested, from the most diverse races, to UlOM which are 

 utterly uiiaistinguishablc ; While, even in the latter case, urgent ana- 

 I . notwithstanding, sometimes for lie a iepantel 



origin ; as when a scries of analogous races Inhabiting d] 

 are compared together, sonu ol which are obs-tonal; different, 

 doubtfully so, and some apparently Identical. Ami It remalni to be 



sh . ivvn whether such intimately allied race! as some of these, even if 

 not descended from a common stock, (.which of course cannot be 



ascertained), would not produce hybrids capable of transmitting and 

 perpetuating the mingled breed. It Is true that Cuvicr guards 

 against this contingency, in the wording of his definition . and that 

 in ost naturalists would concur in regarding such miscible races, how- 

 ever dissimilar, as mrietirt merely of the same : hut a question 

 arises, whether there be not different decreet of fertility in hybrids, 

 corresponding to the amount of affinity, or physiological aceordancy, 

 subsisting betwixt the parent races ; it being only within a certain 

 sphere of that alhnity that they can he produced at all : besides which, 

 as hybrids are seldom exactly intermediate, and in some instances 

 (particularly among multiparous rates I have been known 10 r. .cubic 

 entirely one or the other parent, it may be presumed that this i 

 stance would also materially a:: apabUity of propagation* 



Experiment! are ueeded to solve this important proM> m, though there 

 is ■ very reason to suspect that the I "ill eventu- 



al! v gain the general assent of naturalist.. vi>.. thai uKiU-jnuderailt 

 diuimilaritf don mat oj neceanrp lassv/p apee^eaJ drier,;, y, tne run- 

 mtrm tquaUf < retemblanct jatli 0/ iliel/ to cos 



ititute ipectical identity . — V.V. 



