8 MENDELISM CHAP. 



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 obvious 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 

 century, though such work was almost entirely con- 

 fined to the botanists. Apart from the fact that 

 plants lend themselves to hybridisation work more 

 readily than animals, there was probably another 

 reason why zoologists neglected this form of investi- 

 gation. 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 importance 

 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 of 

 the nineteenth century found the zoologists, under 

 the influence 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 hybridisation which 

 were occupying the attention of some botanists. 

 Nor did the efforts of the botanists afford much 

 encouragement to such work, for in spite of the 

 labour devoted to these experiments the results 

 offered but a confused tangle of facts, contributing 

 in no apparent way to the solution of the problem 



