LEADING GROUPS OF EXISTING SYSTEMS 173 



species to which I would also allude: the fancy that species do not 

 exist in the same way in nature as genera, families, orders, classes, 

 and types. It is actually maintained by some that species are founded 

 in nature in a manner different from these groups; that their exist- 

 ence is, as it were, more real, whilst that of the other groups is 

 considered as ideal, even when it is admitted that these groups have 

 themselves a natural foundation. 



Let us consider this point more closely, as it involves the whole 

 question of individuality. I wish, however, not to be understood as 

 undervaluing the importance of sexual relations as indicative of the 

 close ties which unite, or may unite, the individuals of the same 

 species. I know as well as anyone to what extent they manifest them- 

 selves in nature, but I mean to insist upon the undeniable fact that 

 these relations are not so exclusive as those naturalists would repre- 

 sent them who urge them as an unfailing criterion of specific identity. 

 I would remind those who constantly forget it, that there are animals 

 which, though specifically distinct, do unite sexually, which do pro- 

 duce offspring, mostly sterile, it is true, in some species, but fertile 

 to a limited extent in others and in others even fertile to an extent 

 which it has not yet been possible to determine. Sexual connection 

 is the result or, rather, one of the most striking expressions of the 

 close relationship established in the beginning between individuals 

 of the same species, and by no means the cause of their identity in 

 successive generations. When first created, animals of the same species 

 paired because they were made one for the other; they did not take 

 one another in order to build up their species, which had full exist- 

 ence before the first individual produced by sexual connection was 

 born. 



This view of the subject acquires greater importance in propor- 

 tion as it becomes more apparent that species did not originate in 

 single pairs, but were created in large numbers, in those numeric 

 proportions which constitute the natural harmonies between organ- 

 ized beings. It alone explains the possibility of the procreation of 

 Hybrids, as founded upon the natural relationship of individuals 

 of closely allied species which may become fertile with one another, 

 the more readily as they differ less, structurally. 



To assume that sexual relations determine the species, it should 

 further be shown that absolute promiscuousness of sexes among in- 



