Woodburn. ~ Spermatogenesis in certain Hepaticae. 303 
brane. The details of the formation of the chromosomes from this con- 
dition were not observed. Fig. 7 shows a cell in which the nuclear 
membrane has disappeared and the chromosomes are differentiated. This 
count shows only six, which is two less than the gametophytic number for 
Marchantia and Fegatella. However, this was the only cell found cut in 
such a plane through a dividing cell that the chromosomes could be counted. 
I am not certain, therefore, that six is the exact number. 
The formation of the spindle was not observed, but many sections 
were found showing metakinesis (Fig. 8). The cytoplasm is a little coarser 
in texture than in preceding stages, but otherwise apparently the same. 
Fig. 8 shows numerous granules in the cytoplasm quite similar to those 
shown in Fig. 3. There is nothing to warrant the conclusion that any one 
granule, or body, differs from the numerous other ones, except in size and 
density. All are scattered promiscuously throughout the cytoplasm, some 
in vacuoles, others embedded in the cytoplasmic structure (Figs. 3 and 8). 
Nothing was found in the cytoplasm or at the pole of the spindle which 
resembled a centrosome. The spindle (Fig. 8) stands out clear and distinct. 
The fibres are collected into rather dense, irregular strands which are 
attached to the chromosomes at the plate, while they come to a sharp point 
at each pole. Sometimes one of the irregularly placed granules happens 
to lie near the pole, but no body similar to those shown by Ikeno (’ 03 ) and 
Schaffner (’ 08 ) for the same stages in Marchantia, and by Lewis (’ 06 ) for 
Riccia , was found. Neither were there any radiations from the region of 
the poles. 
Fig. 9 represents an anaphase of one of the earlier spermogenous 
divisions. The cells in one half of the antheridium have reached this stage 
simultaneously. Sharply defined spindle fibres are still attached to the 
ends of the retreating chromosomes. The cytoplasm is more coarsely 
granular, but the largest granules are doubtless oil-drops. The number of 
chromosomes apparent here would indicate that the previous count was 
correct. Fig. 10 represents a telophase following one of the divisions 
shortly before the last. The cells and nuclei are smaller than in earlier 
stages of the antheridium. However, too much significance must not be 
placed in size alone, as this varies considerably for cells of corresponding 
stages in different antheridia. It will be observed that the nucleus which 
shows most nearly the median section has a chromatin network quite 
similar to that in Fig. 3, save that a nucleolus is not visible. 
In Marchantia the resting condition (Fig. 35 a) shows an evident linin 
network containing relatively large lumps of chromatin in a clear nuclear 
sap without any nucleolus. The nucleus seems to pass this stage very 
quickly, while those stages represented by Figs. 25, 26, and 27 persist for 
a longer period. Fig. 25 A is quite similar to Escoyez’s Figs. 7 and 8. 
Ikeno (’ 03 ) does not figure the chromatin in this condition (Fig. 25 a), neither 
