REGENERATION AND DEATH 179 



by the last-mentioned author deserves special men- 

 tion. The investigation of nuclear genesis will lead, 

 I believe, to results of great general biological im- 

 portance. 



We must therefore add to our conceptions in regard 

 to the relations of the nucleus and protoplasm, as 

 quantitatively expressed, this further notion that 

 there is during the early period of development an 

 actual reduction in the size of the nucleus. When 

 this reduction has taken place it is of course evident 

 to any one at all acquainted with the principles of 

 cytology that the cells are in a very different state 

 from theirs before. They are no longer such cells as 

 they were when the nucleus was large, and the nuclei 

 in the different parts of the body alike in character. 

 Here the relations are fundamentally changed. We 

 do not find that these nuclei ever get back from the 

 complex variety of organisation, which they present 

 to us in later stages, to the earlier condition when they 

 were all alike ; yet only with cells of this uniform 

 sort does development begin. We should, therefore, 

 if we reasoned only from the data which I have thus 

 far presented to you, come to the conclusion that 



the Nucleus in the Spinal Ganglion Cells of the Foetal Cat," jfourn. Comp 

 Neural., xiv., 26-48 (1904). 



G. Marinesco, " Recherches sur le noyau de la cellule nerveuse a 1'etat 

 normale et pathologique," Journ. fur Psychol. und Neural., v., 151-172 



Jon G. Lache, " Sur le nucleole de la cellule nerveuse," yourn. de Neu- 

 rologic, 1905, 501-511. 



R. Collin, " Recherches cytologiques sur le developpement de la cellule 

 nerveuse," Le Nevraxe, viii., 181309, pis. iv. vi. (1906). 



