CHAP, ii HISTORICAL 9 



naeus in the latter half of the eighteenth century had given a 

 definite significance to the word species, and scientific men 

 began to turn their attention to attempting to discover 

 how species were related to one another. And one ob- 

 vious way of attacking the problem was to cross different 

 species together and see what happened. This was 

 largely done during the earlier half of the nineteenth cen- 

 tury, though such work was almost entirely confined to 

 the botanists. Apart from the fact that plants lend them- 

 selves to hybridisation work more readily than animals, 

 there was probably another reason why zoologists neg- 

 lected this form of investigation. The field of zoology is 

 a wider one than that of botany, presenting a far greater 

 variety of type and structure. Partly owing to their im- 

 portance in the study of medicine, and partly owing to 

 their smaller numbers, the anatomy of the vegetable was 

 far better known than that of the animal kingdom. It 

 is, therefore, not surprising that the earlier part qf^ the 

 nineteenth century found the zoologists, under the in- 

 fluence of Cuvier and his pupils, devoting their entire 

 energies to describing the anatomy of the new forms of 

 animal life which careful search at home and fresh voyages 

 of discovery abroad were continually bringing to light. 

 During this period the zoologist had little inclination or 

 inducement to carry on those investigations in hybridisa- 

 tion which were occupying the attention of some botan- 

 ists. Nor did the efforts of the botanists afford much 



