Herrick, Physiology of the Nervous Elements. 145 



chology. If it shall be shown that, exclusive of the 

 sensational element alluded to, the emotions are character- 

 ized by judgments (explicate, or more frequently impli- 

 cate) or intellectual processes so abbreviated and condensed 

 as to resemble intuitions, one source of misunderstanding 

 is removed. 



We may conclude with a few concrete illustrations of 

 the processes of proliferation mentioned above. ^ 



The neuroblasts, or future nerve cells, which at first 

 lie in oval interspaces between the bases of the epithelium 

 cells or spongioblasts, soon begin to divide very rapidly, 

 during which process the most beautiful spindle-figures are 

 formed. The chromatin or idioplastic part of the nucleus, 

 which at first was in the form of a loose reticulum, be- 

 comes a regular skein and then divides into two bands 

 arranged in opposing nodes in the two halves of the 

 nucleus, in short, the whole process of karyokinesis is 

 beautifully illustrated and results in two new nerve cells. 

 Thus are formed the two bulging masses of cells of the 

 first embryonic vesicle out of which the corpora striata are 

 produced, and in this way are formed the materials out of 

 which the cerebellum, optic lobes, thalamus, and other 

 regions of the brain are formed. As one follows, step by 

 step, the multiplication, migration and subsequent modifi- 

 cation of these cells, he cannot resist the desire to stimu- 

 late or retard the apparently simple processes upon which, 

 however, the future of the animal depends, or at least to 

 speculate upon the causes which determine the period at 

 which this proliferation of nerve cells ceases in one area or 

 region while it still continues in other. 



In a very young salamander the brain resembles that of 

 an adult fish in the fact that the cortical part of the cerebrum 

 is only represented by a single layer of epithelium. In the 



I. What follows was not printed in the "Quarterly." 



