ANALOGY. 99 



disintegration of albuminous substances begins 

 only after enough micro-organisms are devel- 

 oped to do the work, and that the plant simply 

 assimilates what these lower organisms have 

 set free. The relation between the insectiv- 

 orous plants and the bacteria is one of genuine 

 symbiosis. 



If the whole of Tischutkin's contention is 

 true, the great body of facts brought out by 

 Darwin must still be placed to the credit of 

 analogical reasoning. The facts concerning 

 plant and animal digestion would still remain 

 parallel, both in the succession of the phenom- 

 ena and in the results. It would be another 

 illustration of the vast importance of analogy 

 in scientific method, and of the fact that every 

 analogy, the strongest as well as the faintest, 

 will sooner or later fail. 



In another instance, analogical reasoning 

 from animals to plants actually deterred him 

 from discovering the truth to which other logi- 

 cal processes might have led him. He states 

 the case so clearly himself that it will almost 

 suffice to quote him. 1 "The adaptation of 

 flowers for cross-fertilization is a subject 

 which has interested me for the last thirty- 

 seven years. . . . From my own observations 

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



