Cytology and Movements of the Cyanophycee. 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 Cyanophycee and attributed any 
others to faulty manipulation. He was able to stain all 
granules alike with hematoxylin, 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 hematoxylin might be due to the 
