312 Cuvicrian System of Zoology. 



material bodies can partake of life. Life in general supposes 

 organisation in general, and the proper life of each being sup- 

 poses an organisation proper for that being. We never ob- 

 serve life but in beings completely organised, and made to 

 enjoy it ; and all the efforts of philosophers have not been able 

 to show matter either organising itself, or becoming organised 

 by an exterior cause. 



The birth of organised beings is, therefore, the greatest 

 mystery of organic economy, and of all nature. We see them 

 develope themselves, but we never see their formation. All 

 those whose origin we can trace, have belonged at first to a 

 body of the same form as themselves, but developed before 

 them, or, in other words, to a parent. Before the being has 

 individual life, when it partakes that of its parent, it is called 

 a germ ; the separation of the germ is what is called generation. 

 All organised beings produce their like; without this, death 

 being, as before stated, a necessary consequence of life, the 

 species would become extinct. Organised beings possess, in 

 a variable degree peculiar to each species, the power of repro- 

 ducing certain parts which may be lost ; this is called the 

 power of reproduction. 



The developement of organised beings is more or less rapid 

 and extended, accordingly as circumstances are more or less 

 favourable to their growth. Temperature, and the abundance 

 or kind of food, may aflPect either the whole body, or certain 

 parts : hence the resemblance of the progeny to their parents 

 can never be perfect. The differences of this kind form what 

 are called varieties. 



We have no proof that all the differences which distinguish 

 living beings can ever have been produced by circumstances, 

 as I>arwin and others have maintained. Experience appears 

 to show, on the contrary, that, in the present state of the 

 globe, the varieties are comprised in narrow limits ; and, as far 

 as we can remount into antiquity, we see that these limits were 

 the same as at present. We are, therefore, obliged to admit 

 the existence of certain forms, which have been perpetuated 

 since the creation {depuis Vorigine des ckoses), without ex- 

 ceeding these limits ; and all the beings belonging to one of 

 these forms constitute what is called a species : the varieties 

 are accidental divisions of the species. According to Cuvier, 

 generation being the only means of knowing the limits to 

 which varieties may extend, a species should be defined the 

 7'eunio7i of all the i^idividuals descended from common parents, 

 and of those which resemble them as much as they resemble each 

 other. 



