ME THOD OF STAR TING INVES TIG A TIONS. 5 5 



that here was a fine new field for investiga- 

 tion." His crucial tests only gave him confi- 

 dence that there was more beyond; then he 

 began the long series of observations and 

 experiments which resulted in the charming 

 volume on "Insectivorous Plants." 



It is told elsewhere how he was deterred by 

 theoretical considerations from experimenting 

 on the effects of cross- and self-fertilization, 

 and how the expectation of early results was 

 fairly thrust upon him by the difference in size 

 and vigor between crossed and self-fertilized 

 seedlings. 1 



When once his attention was fixed, he made 

 a preliminary experiment on two plants, with 

 the effects of cross- and self-fertilization as the 

 principal object of investigation. The results 

 corroborated his previous observations, and 

 he was in possession of the principle. Such 

 simple preliminary experiments are interest- 

 ing, since, if they do not establish a principle 

 fully, they raise up for it a higher degree of 

 probability than any succeeding experiments, 

 and make it possible to work deductively with 

 considerable confidence. 



The introduction of the principle of con- 

 tinuity into general scientific thinking has 



1 Effects of Cross- and Self-Fertilization, pp. 6-8. 



