go BOTANCIAL GAZETTE [FEBRUARY 
division. This irregularity is probably connected with the failure 
in pollen development. 
The cytoplasm of the mother cells in the ‘‘resting”’ condition con- 
tains numerous large spherical starch grains. In safranin-gentian 
they stain pale blue and the central hilum is made more prominent by 
its retaining a highly refractive globule of xylol. These starch grains’ 
are thus very conspicuous objects in the mother cells (fig. 3). With 
iodine they appear brown and angular, and the iron-haematoxylin 
stain leaves them invisible, so that very different appearances of the 
mother cells are obtained according to the method of treatment. Dur- 
ing the prophases of the first mitosis the starch grains become more 
abundant, until the cytoplasm is literally packed with them. This 
reserve store of nutriment is used up during the reduction divisions, 
and no starch grains are to be seen in the pollen tetrads. In iron- 
haematoxylin the cytoplasm of the pollen mother cells frequently 
presents a rather obscurely radiate appearance during the pre-synaptic 
stages. In the earlier or “resting” condition of the nuclei in the 
mother cells they contain one large nucleolus, which is commonly 
placed near the nuclear wall and contains one to several vacuoles of 
varying size with highly refractive walls (fig. 9). In addition, two 
or more smaller chromatic bodies are usually found distributed near 
the nuclear membrane. They appear connected and often surrounded 
by the delicate reticulum scattered through the nucleus. The large 
nucleolus is several times the size of the smaller bodies. Sometimes 
it is in the center of the nucleus, and the smaller bodies are appressed 
to the nuclear wall. Vacuoles are usually observed only in the large’ 
nucleoli, but occasionally minute ones may be seen in the smaller 
chromatic bodies. More rarely two large nucleoli of nearly equal 
size may be found. The small round chromatic masses arise from 
the more angular chromatic bodies found at the nodes of the reticulum 
in an earlier stage (jig. 8). These bodies probably correspond to 
OvERTON’s “‘prochromosomes,” though they have not been studied 
fully. The next stage leading towards the synapsis condition is 
apparently the beginning of contraction of the nuclear reticulum. The 
nuclear membrane is often extremely delicate at this time, and as 
indicated in fig. ro, the nucleolus is frequently surrounded by a com- 
pact reticulum which has contracted from the nuclear membrane, 
