I QO THE METHOD OF DARWIN. 



his own theories were innumerable; some of 

 them he answered by the great investigations 

 already mentioned, others he left unanswered 

 for various reasons. Only about two months 

 before his death he pointed out new lines of 

 investigation. Among other things he said 

 that there were many inconspicuous flowers not 

 known to be visited by insects during the day, 

 and the natural inference is that they are self- 

 fertilized. And he pointed out the desirability 

 of finding out whether these flowers are visited 

 at night by the innumerable individuals of the 

 many species of minute moths. If they are not 

 so visited, why do they expand at all ? Why 

 are they not cleistogamic ? He suggested, as a 

 mode of procedure, smearing the flowers with 

 viscid matter and then looking for insect scales; 

 but gave the caution that it would be necessary 

 to prove that the matter employed was not in 

 itself attractive to insects. 1 



It is a fascinating study to follow out the 

 suggestions that came to him and that he made 

 to others, to note the various degrees of success 

 with which the investigations were made by 

 others, to compare the spirit and methods with 

 which they were made with Darwin's own spirit 



1 Miiller, Fertilization of Flowers, Prefatory Note, by 

 Charles Darwin. 



