The Organism and its Major Parts 35 



docs not prove it false. Since, as we have previously seen, 

 Schleiden's brand of clementalism necessitated the sacrifice 

 of the individuality of the plant to that of the cell, our 

 critical examination of it belongs properly to our examina- 

 tion of the cell-theory. Here, consequently, we do no more 

 than point out that Schleiden himself did not succeed in 

 carrying through fully his simple denial of the plant's unity. 

 The oneness of the young dciwloping plant was an obstacle 

 to his theory, even though he seems not to have been aware 

 of the fact. "After the woody mass is formed, we miss," 

 he says, "the influence of the law of formation, which until 

 then had without exception directed the growth of the entire 

 plant in all its parts." 5 



Schleiden seems to have felt no difficulty in his conception 

 that the "law of formation" which "directed the growth of 

 the entire plant in all its parts" could be accounted for by 

 the "separate cell," the only individual "in a strict sense." 

 His immunity from qualms on this score was due probably 

 to the fact that, being an "ultimate problem" botanist in- 

 stead of a naturalist really interested in plants, it did not 

 occur to him that the question of how the cells could explain 

 the fact that in one instance the "entire plant in all its 

 parts" should IK- an apple tree, in another an oak tree, in 

 a third an orange tree, and so on, might be considered a 

 really important one by somebody. 



We now pass to the examination of a single modern in- 

 stance of the attempt to "explain away" the individuality 

 of the plant. The principle made use of in this attempt is 

 that of symbiosis, which is a sort of partnership between 

 organisms of different species, so close in some cases as to be 

 really organic. Although I do not know that the example 

 I have chosen has had much recognition among botanists, it 

 yet seems justifiable to use it since it is certainly typical, 

 even though possibly somewhat extreme. It is taken from H. 

 C. Davidson, an English botanist, his publication being en- 



