99 
Woodburn. — Spermatogenesis in B Iasi a pusilla , L 
sperms, sections or fragments of the cilia are found in abundance, indicating 
form, position, and number similar to those for other described Hepaticae. 
Summary. 
The mitotic stages in the spermogenous tissue show no indications of 
centrosomes, the divisions occurring in the usual manner. 
The spindle of the last division may be placed obliquely, but this does 
not seem to be always the case. A pair of spermatids, however, results 
from each cubical cell. An individual membrane surrounds each spermatid, 
but no wall separates the two, as is the case in Polytrichum (Allen, T2). 
The blepharoplast makes its appearance first as a dense area of cyto- 
plasm in opposite ends, respectively, of each of the pair of spermat'ids. 
Gradually a definite granule or body is differentiated, which develops as 
a thread or cord around the cell near to the plasma membrane. This cord, 
the blepharoplast, stains homogeneously throughout. Following its course 
the nucleus lengthens in close contact with the blepharoplast, the two 
become indistinguishable by the time one complete turn is made, and the 
body of the sperm which stains like chromatin continues to increase in 
length until the mature form is reached (Fig. 14). Two cilia are developed, 
probably, from the forward end of the blepharoplast. 
No accessory bodies of any sort corresponding either to the ‘Neben- 
korper ’ of Ikeno or the 4 limosphere ’ of Wilson are differentiated. 
Discussion. 
It is of some interest to note how similar the phenomena are which 
occur in the spermatogenesis of various Liverworts. However, we would 
expect to find this similarity in the reproductive cells of plants so closely 
related. Possibly the main point of difference between certain ones — Blasia 
and Porella , for instance — is found in the larger size of the sperm body of the 
former. A larger amount of chromatin, however, seems to exist in the 
spermatid, and in those stages which lead up to the mature form. The 
mere matter of size does not seem to be a fundamental difference. A 
phenomenon of more importance is the appearance of a polar body during 
the diagonal division in Marchantia. But if this body does not have 
morphological continuity, as my observations led me to believe, there is 
some question as to how much importance should be attached to it, 
unless an interpretation be placed upon it different from that given by 
former writers. It is of interest to recall the fact that of the thallose 
Hepaticae, Marchantia possesses the most highly differentiated gameto- 
phyte as regards its general morphology, histology, and the occurrence 
of centrosomes in the vegetative tissue (Van Hook). The last-named 
cytological phenomenon, together with the appearance of polar bodies 
in the metakinesis of the last division of the spermogenous tissue, may be 
a concomitant of the morphological and histological differentiation. 
H 3 
