306 Woodburn. — Spermatogenesis in certain Hepaticae. 
is not shown by their position, as the rounded pairs lie variously placed 
within the antheridial cells, whose walls are also somewhat rounded off 
(Fig. I 3)- 
As already described by Ikeno and others, the last division of the 
spermogenous tissue, in Marchantia , , is a diagonal one which separates the 
cell contents into a pair of triangular sperm cells not separated by a cell- 
wall. The oblique position of the spindle has also been accurately described. 
In some respects, however, my observations differ from those of the other 
observers. Cells that are ready to enter upon this division have usually 
a more coarsely granular cytoplasm than those in early stages of spermo- 
genous development. The cytoplasm becomes more vacuolate, and the 
denser areas tend to collect in aggregations of granules, or in definite bodies 
(Fig. 30). There are usually two rather larger, dense bodies of about equal 
size, lying on opposite sides of the nucleus, and usually opposite the angles 
of the cell-wall. Smaller ones, which apparently differ only in size, are also 
found in the cytoplasm. Fig. 29 shows spindle fibres beginning to form 
from the immediate region of one of these larger bodies. Comparing 
Figs. 31 and 32, we see that the fibres reach down around the nuclear 
membrane, which soon disappears, and the fibres will enter the nuclear 
cavity and become attached to the chromosomes. Fig. 32 shows an inter- 
mediate stage in the formation of the spindle, in which the nuclear mem- 
brane is evidently gone, but where the chromosomes are neither fully 
differentiated nor attached to the spindle fibres. During this stage the 
bodies occupying the poles of the spindle are quite conspicuous. In Figs. 33 
and 34 the chromosomes, while each one cannot be distinctly made out, are 
evidently arranged in an equatorial plate. Nearly every spindle has at 
least one body at the pole. Sometimes (Fig. 34) more than one body 
occurs with the spindle fibres attached to each. On the other hand, a single 
body may be present with few of the fibres attached to it, while the rest 
evidently extend beyond, often forming a broad pole (Fig. 33). These 
bodies as a rule do not stain as deeply in metakinesis as during prophase. 
Figs. 29-37 were drawn from the same slide, and consequently had received 
the same treatment in staining. After metakinesis these bodies do not 
persist with any regularity. Sometimes they may be seen in anaphase and 
telophase, but more frequently they cannot (Figs. 35, 36, and 37). I could 
find no evidence that the body, which occupies the pole of the spindle 
during the diagonal division, persists as an individual organ in the resulting 
sperm cell, as stated by Ikeno (’ 03 ), Escoyez (’ 07 ), and Schafifner (’ 08 ) for 
Marchantia , Bolleter (’ 05 ) for Fegatella , and Lewis (’ 06 ) for Riccia natans . 
At a later stage a definite body is found in the sperm cell, but no certain 
connexion can be traced between this body and the one which earlier occu- 
pied the spindle pole in the diagonal division, further than the fact that 
they both appear in the cytoplasm of the cell concerned. The cytoplasm 
