64 Ox\ VARIETIES, RACES, SUB-SPECIES, AND SPECIES. 



species ; but it must not be forgotten that hybrids, especially of 

 the animal creation, have little disposition to multiply. Lastly, 

 if it be remembered that reproduction is only possible between 

 closely-allied species, it will be seen that the notion of species 

 deduced from the preceding remarks may be clearly given in the 

 following terms : — 



A species comprehends all the individuals proceeding from 

 the same male and the same female ; these individuals resemble 

 them as much as possible relatively to the individuals of other 

 species ;* they are then characterised by the resemblance of a 

 certain generality of mutual relations existing between the organs 

 of the same name, and the differences which arise out of these 

 relations constitute varieties in general. 



Varieties are called simple if the diffei'ences are not perpe- 

 tuated by generation, or, if they are, then only in a very small 

 number of circumstances which are not identical ; they consti- 

 tute races if the differences, taken as a whole, are pronounced, 

 and of such a nature as to be perpetuated by reproduction, and 

 that pretty constantly in a certain number of circumstances that 

 are not identical ; they constitute lastly sub-species, if the cha- 

 racteristic differences being well pronounced, are perpetuated 

 constantly in all the circumstances in which the individuals 

 composing the species can exist. 



If the definition of species wliich we have offered cannot be 

 literally the object of a rigorous demonstration, in consequence 

 of the impossibility of proving that there ^vere originally , for each 

 species of livi?ig body, but one or two individuals, in attri- 

 buting their origin to a period when they acquired the form 

 which we now see, whether they underwent any modifications 

 prior to tliis period, or whether they were created with their 

 actual form ; and if in this respect our definition be somewhat 

 hypothetical, we have adopted it without hesitation, because it 

 sums up our opinion with as much conciseness as clearness, with- 

 out affording room for any erroneous interpretation ; for the 

 foundation of the whole clearly remains, whether each species 

 received its actual form in a single individual or a single couple, 

 or whether it received it in several individuals or in several pairs 

 of individuals. 



Of the two things which we regard in a species, the first is 

 the only one which has been studied with any care by the nu- 

 merous naturalists to whom we are indebted for the description 



* In this resemblance we include all the characters ; for if we only con- 

 sider the visible characters, as shape, size, and colour, we may find more 

 resemblance, in these respects, between two individuals of different species 

 than between the individuals of two races of one and the same species. For 

 example, a mastiff, variety of dog, resembles a wolf more than a spaniel. 



