Anctbolism and Specialisation. 201 



the onset of specialisation and maturity. Embryonic life 

 with the continually added nutrition, and its result the 

 rapid growth and slow specialisation with the acquirement 

 of great size, is to be contrasted with the highest forms of 

 metamorphosis, where a previously w^ell-nourished larval 

 form is suddenly completely checked in any further addition 

 to its nutrition, with the result we see in the extremely 

 rapid specialisation with some diminution in bulk. The 

 body size depends chiefly on the number of cell divisions 

 and not on the size of the cells. The tendency to division is 

 most intense at first, and gradually diminishes until adult 

 existence, when some of the cells, e.g., nerve cells, apparently 

 stop dividing.^ It would follow from this that the size 

 acquired by the body would depend upon the length of time 

 that the stage of intensity of cell division could be pro- 

 tracted, or, in other words, the length of time that a simpler 

 anabolism could be kept up, and prevented from passing 

 over into the stage of anabolism of greater instability. This 

 would largely depend on the duration of embryonic life, 

 and the effective degree to which the nutrition could be 

 brought. 



To turn for a moment to the effect of lowered nutrition on 

 the nervous system, and some of the effects produced by 

 poisons. There is no doubt that sensibility, or what might 

 be called the instability of the nervous tissue, is greatly 

 heightened by hunger and starvation. Pain is always 

 agoravated under conditions of bad nutrition. Death from 

 starvation is said to take place in a fit of maniacal delirium 

 or in horrible convulsions. It seems likely that epilepsy 

 and states of defective inhibition are due to an extreme 

 instability of the nerve cells in certain parts of the brain, 

 and that this instability would be heightened by impoverished 

 nutrition, and lessened by an excessive food supply. In- 

 organic substances which are poisonous, and act by causing 

 great chemical changes in the protoplasm, have, of course, 

 much the same action on all living material, and the same 

 may be said for those organic substances which act by 

 complete and sudden extraction of the water. There are, 



^ See "The Cell in Development and Inheritance" (Wilson). 



