Cytology and Movements of the Cyanophycece. 253 



the functions of the chromatin, but was not that substance. 

 No nuclear wall was present, hence he suggested that the 

 nucleus be called an "open nucleus" in distinction to the 

 "closed nucleus" of the higher plants. In cell division the 

 cell wall grew inward, gradually constricting the spirem-like 

 nucleus until it was finally separated into two parts. A 

 chromatophore was also described, consisting of small gran- 

 ules of chlorophyll joined together like a string of beads, 

 and ramifying through the outer cytoplasm in which the 

 blue coloring matter, phycocyanin, was dissolved. These 

 chlorophyll grains were connected with the skein-like 

 nucleus by similar threads. This observation is very inter- 

 esting in the light of the recent work of Watson (81) per- 

 formed in this laboratory. Watson has shown that the 

 plastids of higher plants are probably derived from the 

 nucleus and are connected with it by protoplasmic threads, 

 but whether the observations of Hieronymus can be looked 

 upon as an earlier type of what Watson has found in the 

 higher plants remains for further investigation. Hierony- 

 mus considered the granules of the cytoplasm to be the 

 "cyanophycin granules" of Borzi, or what were denomi- 

 nated "granules" by Zacharias and "red granules" by But- 

 schli. These granules he considered to be neither reserve 

 food nor the products of assimilation, but that they were 

 unwound from the "central body." They were crystalloid 

 and angular, crystallizing after one of the regular systems, 

 according to their chemical composition. Immediately 

 within the cell wall was a thin hyaline layer enveloping the 

 protoplasm. In answer to a criticism by Zacharias (91) 

 Hieronymus (40) still maintained that there was but one 

 kind of granule in the Cyanophyceae and attributed any 

 others to faulty manipulation. He was able to stain all 

 granules alike with haematoxylin, if he used ammonia after- 

 wards. This treatment, however, would seem scarcely per- 

 missible for the reason that the red staining reaction of 

 granules by means of haematoxylin might be due to the 



