1875.] FERTILISATION OF FLOWERS. 431 



doubtless because they were convenient objects for studying 

 organic phenomena in their least complicated forms ; and 

 this point of view, which, if one may use the expression 

 without disrespect, had something of the amateur about it, 

 was in itself of the greatest importance. For, from not being, 

 till he took up any point, familiar with the literature bearing 

 on it, his mind was absolutely free from any prepossession. 

 He was never afraid of his facts, or of framing any hypothe- 

 sis, however startling, which seemed to explain them. . . . 

 In any one else such an attitude would have produced much 

 work that was crude and rash. But Mr. Darwin if one may 

 venture on language which will strike no one who had con- 

 versed with him as over-strained seemed by gentle persua- 

 sion to have penetrated that reserve of nature which baffles 

 smaller men. In other words, his long experience had given 

 him a kind of instinctive insight into the method of attack of 

 any biological problem, however unfamiliar to him, while he 

 rigidly controlled the fertility of his mind in hypothetical 

 explanations by the no less fertility of ingeniously devised 

 experiment." 



To form any just idea of the greatness of the revolution 

 worked by my father's researches in the study of the fertilisa- 

 tion of flowers, it is necessary to know from what a condition 

 this branch of knowledge has emerged. It should be remem- 

 bered that it was only during the early years of the present 

 century that the idea of sex, as applied to plants, became at 

 ail firmly established. Sachs, in his ' History of Botany ' 

 (1875), has given some striking illustrations of the remark- 

 able slowness with which its acceptance gained ground. He 

 remarks that when we consider the experimental proofs given 

 by Camerarius (1694), and by Kolreuter (1761-66), it appears 

 incredible that doubts should afterwards have been raised as 

 to the sexuality of plants. Yet he shows that such doubts 

 did actually repeatedly crop up. These adverse criticisms 

 rested for the most part on careless experiments, but in many 

 cases on d priori arguments. Even as late as 1820, a book of 

 this kind, which would now rank with circle squaring, ox 



