ioo Woodburn. — Spermatogenesis in Blasia pusilla, L. 
Certain developments in Pellia , Mnium, and A trichum , described by 
Wilson, form a very striking contrast to those which take place in forms 
very closely related, at least to Pellia , such as Blasia and Porella. One 
might expect to find somewhat varying developments on passing over into the 
Musci. Wilson did not figure the mature sperm in any of the three plants 
discussed, but the writer finds little difference between the mature sperms 
of Funaria and those of the Liverworts previously described and figured 
( Fl 'g- I 5)- 
The sperm of the Bryophyta is a model of simplicity and adaptation, 
and the mature form, which is so admirably suited to the conditions to be 
met and functions to be exercised, is reached by a very direct and yet 
gradual transformation. The blepharoplast apparently arises de novo 
as the result of the differentiation of active cytoplasm in the cell in which 
it is to function. It seems quite probable that the blepharoplast represents 
not only a cilia bearer, but also a formative portion or region of the proto- 
plasm, which in some manner directs the growth of the spermatid as regards 
form. It seems quite probable also that, in some cases at least, the actual 
bulk of the chromatin may be increased at the expense of the cytoplasm. 
The evident results, of vital relation to the plant’s economy, reached by the 
transformation of the spermatid into the mature form of the sperm, seem to 
be the preparation of as large an amount of chromatin as possible to be 
passed into the egg-cell, in a form best adapted to the movements necessarily 
executed in reaching the latter as quickly as possible. The contour of this 
form is mapped out by the developing blepharoplast ; the form of the nucleus 
becomes moulded accordingly, and the larger part, if not all, of the cyto- 
plasm is used up in the production of energy for the processes going on, 
or else become differentiated, adding to the nuclear material of the blepharo- 
plast. There is good evidence that quite a large portion goes to the 
development of the latter. There seems to be no evidence, in the material 
I have examined, of chromatin passing out into the cytoplasm. We 
would hardly expect such to be the case as the nucleus seems to increase 
rather than decrease in size and staining capacity. 
North-Western University, 
Evanston, III. 
Bibliography. 
Allen, Charles E. (’ 12 ) : Cell Structure, Growth, and Division in the Antheridia of Polytrichum 
juniperinum , Willd. Archiv fiir Zellforschung, Band viii, Heft I, pp. 121-88. 
Ikeno, S. (’ 03 ) : Die Spermatogenesis von Marchantia polymorpha. Beihefte zum Botanischen 
Centralblatt, vol. xv, 1903, pp. 65-88. 
