Nos. 451-452.] AMERICAN SOCIETY OF ZOOLOGISTS. 515 



the nucleus. These processes are so dehcate and the granules 

 bounding them so small in comparison with the chromatin gran- 

 ules in the network, that they are invisible except in sections. 

 The location of large chromatin granules continuous with tlic 

 nuclear reticulum, in the indentations of the halo, explains iis 

 circular appearance in entire preparations, because these gi annles 

 are the only parts of the outline visible. They also alloid an 

 explanation of the irregular outline itself, for if we imagine a 

 sphere of liquid to proceed out from the nucleolus in all direi - 



tions, any larger objects with whici 

 would, after yielding as much as j)( 

 certain points, allowing it to advai 

 resistance, viz., between the larger 

 the projections of the halo end distal 

 vac) which, apparently through the a, 

 of the nuclear reticulum, become coi 

 wards be found loose in the nuclei; 

 they may finally escape (C, vac"). 

 tions of the halo may break throu; 

 before the vacuoles separate (B, vad 



