FINAL CAUSES 129 



till it reaches the fundamental and physical basis of life, 

 or the protoplasmic cell ; and science declares that this 

 analysis leaves no room for ends, but can find nothing 

 but causes and effects. Hence once more do we ulti- 

 mately arrive at the potentiality of protoplasm, and all I 

 claim is, that, given certain, nay, almost any, combinations 

 of conditions of the environment, protoplasm will respond 

 and do such or such a work, the outcome of which is an 

 organ adapted to its environment, and finally an organism 

 which then "imperiously" asserts to us its finality. 



We thus arrive at the last question, Whence comes 

 this potentiality of protoplasm ? or, How is it that 

 orderly differentiation comes out, and not perpetually 

 changing states of chaos ? As a fact, the more differ- 

 entiation has set in, the more wonderful are the structures 

 produced ; so that, casting the eye back through the 

 vista of past ages, from the most primitive creature to 

 man, we see as a rule nothing but ascending series in 

 every direction. 



Science knows nothing of "must". All that we can 

 say is, that such or such organs do grow in an embryo, 

 and that collectively they do make an organism, but 

 they may at any time make a monster instead. 



Thus normally the tissue of a leaf-bud is formed in a 

 certain way ; but a cynips punctures it and deposits an 

 sgg within. The tissues now grow abnormally and pro- 

 duce a gall. The inner layers of this contain nutritive 

 food suitable for the grub, and upon which it lives. If 

 the nourishment were not specially provided by the 

 tree, the grub could not live. This is a case which 

 shows how the gall is apparently nothing but an 

 effect or result of a mechanical injury caused by the 

 puncture. But looking at the gall per se, we find it 

 furnishes board and residence for the cynips. Here 



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