152 THE TEACHING BOTANIST 



course animals are entirely dependent for their food 

 upon that made by plants. 



Another error is the assumption that the carrying 

 of pollen from flower to flower by insects is a part of 

 the process of reproduction, and this is intensified by 

 the common expression of " cross-fertilization ' used to 

 describe the process. But really this process has 

 nothing directly to do with the act of fertilization, but 

 it is simply one of the methods the plant has adopted 

 to overcome the difficulties imposed by the sessile habit ; 

 that is, it is the mode of locomotion of the male to the 

 female element, and is much better described as pollen- 

 locomotion or cross-pollination. 



When one studies the phenomena of irritability, he 

 usually passes through a stage in which he believes that 

 plants possess a certain intelligence. The more careful 

 study of the phenomena, however, leads to the conclu- 

 sion that it is not intelligence they possess, though they 

 have a power producing some apparently similar results. 

 Irritability is more nearly comparable with reflex action, 

 and even with instinct in animals, than with their con- 

 sciousness and intelligence. It may be said that out of 

 one and the same property in the original protoplasm, 

 animals have differentiated reflex action, instinct, and 

 intelligence, while plants have developed irritability. 



It is only by keeping in touch with the most modern 

 and authoritative books that the teacher can correct the 

 older errors. 



