444 
IVoodburn.—Spermatogenesis in 
bounded apparently by a very delicate plasma membrane, and situated 
somewhere within the cytoplasm there appears quite early a conspicuous 
dark staining body, usually more or less spherical at first, the blepharoplast. 
The origin and nature of this body is as yet a matter of dispute. It 
evidently functions in the development of the cilia, and whether it has to 
do with the growth processes of the latter or with the change in form of the 
cell, it or some portion of it certainly forms the base of attachment for the 
cilia. 
The two stages wherein there seems to be more general agreement, the 
androcyte and the mature sperm, may be considered momentarily resting 
or fixed conditions, that is, for a very short time at least, there seems to be 
no noticeable change of form or internal structure. This may account for 
the fact that these two stages appear to be most constant throughout 
the various genera of the Bryophyta. It is during the very active conditions 
of karyokinesis which lead directly to the formation of the androcytes, and 
during the transformation of the androcyte into the mature sperm when the 
internal cell structures are rapidly changing and are certainly in an exceed¬ 
ingly high state of plasticity, that decidedly varying observations have been 
recorded. These facts, coupled with the extremely small size of the cells, 
make it rather difficult to follow with certainty the minute details of 
development. 
The writer has been engaged for some time past in studying spermato¬ 
genesis in certain of the Musci, especially in Mmum affine , var. ciliaris . 
While it seems quite probable that many things have been elusive, and 
doubtless there is much yet to be recorded, it seemed wise to present 
here a few observations. 
The antheridial heads were killed in chrom-osmic-acetic acid according 
to the formula of Mottier ( 4 ), washed, dehydrated, and embedded in 
paraffin in the usual way. The sections were for the most part cut five 
microns thick. For staining purposes aniline-safranin and gentian-violet 
were used with good results, also Haidenhain’s iron-alum-haematoxylin 
counterstained with Bismarck brown. The best material was secured and 
fixed in the field one afternoon, May io, after a heavy rain with the 
temperature near 70° Fahrenheit. The tissues were well supplied with 
water, the plants were in good condition, and many dividing nuclei were 
found. While the Moss has developed considerable adaptation to drought, 
yet it is noticeable that the tissues respond very quickly to changes in 
moisture. 
Certain slides were also prepared of sperms which were allowed to 
escape in a drop of water, and while in the free swimming state killed with 
2 per cent, osmic acid. These were stained with aniline-safranin and 
gentian-violet. 
