36 ZOOLOGICAL PHILOSOPHY 



was still almost negligible. It is continually being discredited for 

 those who have seen much, who have long watched nature, and who 

 have consulted with profit the rich collections of our museums. 



Moreover, all those who are much occupied with the study of natural 

 history, know that naturalists now find it extremely difficult to decide 

 what objects should be regarded as species. 



They are in fact not aware that species have really only a constancy 

 relative to the duration of the conditions in which are placed the 

 individuals composing it ; nor that some of these individuals have 

 varied, and constitute races which shade gradually into some other 

 neighbouring species. Hence, naturahsts come to arbitrary decisions 

 about individuals observed in various countries and diverse con- 

 ditions, sometimes calhng them varieties and sometimes species. The 

 work connected with the determination of species therefore becomes 

 daily more defective, that is to say, more compUcated and confused. 



It has indeed long been observed that collections of individuals 

 exist which resemble one another in their organisation and in the 

 sum total of their parts, and which have kept in the same condition 

 from generation to generation, ever since they have been known. 

 So much so that there seemed a justification for regarding any col- 

 lection of Uke individuals as constituting so many invariable species. 

 Now attention was not paid to the fact that the individuals of the 

 species perpetuate themselves without variation only so long as the 

 conditions of their existence do not vary in essential particulars. 

 Since existing prejudices harmonise well with these successive 

 regenerations of hke individuals, it has been imagined that every 

 species is invariable and as old as nature, and that it was specially 

 created by the Supreme Author of all existing things. 



Doubtless, nothing exists but by the wiU of the Subhme Author 

 of all things, but can we set rules for him in the execution of his will, 

 or fix the routine for him to observe 1 Could not his infinite power 

 create an order of things which gave existence successively to all that 

 we see as weU as to all that exists but that we do not see ? 



Assuredly, whatever his will may have been, the immensity of his 

 power is always the same, and in whatever manner that supreme 

 will may have asserted itself, nothing can diminish its grandeur. 



I shall then respect the decrees of that infinite wisdom and con- 

 fine myself to the sphere of a pure observer of nature. If I succeed 

 in unravelhng anything in her methods, I shall say without fear of 

 error that it has pleased the Author of nature to endow her with that 

 faculty and power. 



The idea formed of species among living bodies was quite simple, 

 easy to imderstand, and seemed confirmed by the constancy in the 



