An Introduction to a Biology 



the human mind. I do not maintain that these 

 problems are entirely fictitious. I do not mean 

 that they bear no sort of relation to the real problems ; 

 I think they are a distorted version of the real 

 problems, that they may be said to bear the same 

 sort of relation to the real problems as the tune 

 begun on the wrong note bears to the real tune. 

 But, of course, some biological problems have been 

 stated more correctly than others. 



The history of biology is a picture of the evolution 

 of man's endeavour to interpret life. The picture of 

 this evolution, as of all other evolutions, is the picture 

 of a tree : leaves, twigs, branches, trunk, root, root- 

 lets and root-hairs. This tree is the result of the 

 solidification of the stream of mankind's interest in 

 life. The root-hairs are his first vague curiosity and 

 bewilderment ; the leaves his most recent publica- 

 tions and opinions ; intervening points on the 

 branches, trunk and roots, intervening periods in the 

 history of biology. We will imagine further that 

 discredited observations and unaccepted interpreta- 

 tions were represented in this tree by dead wood, 

 which quickly rotted and fell away. 



It seems to me desirable that we should occasion- 

 ally tear ourselves away from pre-occupation with 

 the high-water mark of our investigations ; that we 

 should cease for a moment from our feast upon the 

 leaves, and descending to the ground, reflect at 

 leisure, under its genial shade, upon the form of the 

 tree above us. Eeclining there, we should ask our- 

 selves whether the shape of the tree into which the 

 course of the stream of inquiry has solidified, is the 

 right shape, whether some of the wood in it ought 



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