Spermatogenesis in Blasia pusilla, L. 
BY 
WILLIAM L. WOODBURN. 
With Plate XI. 
I N a recent paper I discussed spermatogenesis in Porella , Marchantia , 
and Fegatella. The essential features in the development of the 
sperm were found to be quite similar in these three Liverworts. I came 
to the conclusion that f we may consider the mature sperm to represent 
the two constant cell elements, nucleus and cytoplasm ; the main body 
or nuclear portion representing the nucleus, the blepharoplast and cilia 
representing specialized parts of the cytoplasm, and the remainder of 
the latter being found in the cytoplasmic vesicle’. In Marchantia and 
Fegatella the last division of the spermogenous tissue results in a pair of 
triangular-shaped spermatids in each cubical cell. No cellulose wall 
separates the members of the pair, but each is surrounded by a plasma 
membrane, and becomes directly transformed into the mature sperm. In 
Porella the last division is not constantly in a diagonal plane, but the 
fundamental features seem to be the same. The phenomena which have 
caused the greatest amount of discussion are the origin and nature of the 
blepharoplast, and the origin and nature of the polar body occurring in 
certain mitotic stages of Marchantia , Fegatella , Riccia, and certain of the 
Musci. The various views of the more recent writers were discussed in my 
former paper. Evidence obtained in my previous studies* indicated the 
origin of the polar or centrosome-like body as a differentiation of cyto- 
plasmic or kinoplasmic materials. It apparently does not possess morpho- 
logical rank, as its genetic continuity could not be established from an 
examination of closely consecutive mitotic stages. If such a body does 
exist from one cell generation to the next its chemical nature evidently 
changes greatly, so as to cause it, at times, to lose entirely its staining 
capacity. During metakinesis in spermogenous tissue of Marchantia , 
Fegatella , and Porella , no centrosome-like bodies were found. During the 
diagonal division those which occur do not show evidence of a centrosome 
nature, and do not persist, at least with staining capacity, during telophase. 
The blepharoplast begins its development in the spermatid as a dark, 
deeply stained granule in a dense area of cytoplasm. It would seem that 
[Annals of Botany, Vol. XXVII. No. CV. January, 1913.] 
