THE GENESIS OF LIVING ORGANISMS 225 



generates. In the case of sensory cells, almost the whole 

 becomes receptor ; in the nerve-cells, almost everything is a 

 path of conduction ; and in the muscle-cells, it is practically 

 all effector. The same law can be shown to hold good for 

 the cells of the vegetative organs. 



Thus each cell remains an autonomous subject, the frame- 

 work of which, in contrast to free-living cells, insinuates itself 

 into a surrounding- world which is itself a subject. 



For the sake of simplicity, we have hitherto assumed 

 that the subject of the germ itself is the same as that of the 

 full-grown organism, and has merely invested itself with all 

 the necessary properties, so as to exercise in .fuller degree 

 fundamentally similar functions. But now we see that it 

 cannot be the same subject, because thousands of generations, 

 which have arisen by division of parent-cells into daughter- 

 cells during the interval, lie between the two. And finally, 

 the full-grown subject is not merely one of the thousandth 

 generation, but embraces all the millions of offspring that 

 have arisen through the thousandfold reproduction. 



If we let an amoeba divide as often as this, and then 

 consider all its offspring together, these do not form a coherent 

 subject, but are merely millions of similar cells. In contrast • 

 to the thousandfold division of the amoeba, which always pro- 

 ceeds in accordance with the same law, the division of the 

 germ constitutes quite a different process. It is governed by 

 two sets of laws, which direct the individual daughter-ceUs to 

 definite places, and, when they have arrived there, compel 

 them to take on a definite form. We have seen that this pro- 

 cess is controlled by a series of polar impulse-systems released 

 rhythmically. The second set of laws affects the internal 

 changes in the individual cell-subjects, which, as they shift 

 towards their definitive position, slowly become poorer in 

 genes, until at last, having reached their goal, they have but 

 one left ; this gene assumes the work of their inner shaping.. 



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