288 Allen . — The Spermatogenesis of Poly trichum juniperinum. 
Summary. 
Each newly formed androcyte of Poly trichum juniperinum contains 
a small rounded blepharoplast which behaves like a centrosome in the 
division of the androcyte mother-cell, and which in most cases still lies in 
the region recently occupied by a spindle pole. 
The blepharoplast elongates, places itself in contact with the plasma 
membrane, and ultimately forms a long, peripherally placed, curved cord. 
Two long cilia grow out from it ; their point of attachment is a short 
distance behind the anterior end of the blepharoplast. 
The nucleus moves into contact with the blepharoplast and stretches 
out along the latter. The blepharoplast, though visible until a comparatively 
late stage, ultimately becomes indistinguishable from the nucleus except for 
its anterior end, which apparently projects a short distance beyond the tip of 
the elongated nucleus. The nucleus becomes a long, slender, coiled, finally 
homogeneous body, of about one and one-half turns. The nucleus and the 
blepharoplast seem to constitute the whole of the body of the mature 
antherozoid. 
At about the time the blepharoplast begins to elongate, a large, spherical 
body, the limosphere, appears, variously situated in the cytoplasm ; soon it 
comes to lie close to the anterior end of the blepharoplast. In this position 
it divides unequally ; its smaller portion becomes the apical body, its larger 
retains the appearance of the limosphere before the division and is referred 
to by the same name. 
The apical body remains applied to the anterior end of the blepharo- 
plast until a very late period, but it has not been clearly shown to take any 
part in the formation of the body of the antherozoid. 
The limosphere, after the formation of the apical body, takes a position 
in contact with the nucleus, nearly always with the posterior portion of the 
latter. The limosphere persists in the cytoplasm until the time of the maturity 
of the antherozoid. 
During certain stages in the history of the androcyte, another conspicuous 
cytoplasmic body, the percnosome, seems to be regularly present. It is 
probably identical with a smaller granule which is generally recognizable 
both at an earlier and at a later period. This smaller body sometimes — at 
very late stages usually, if not always — lies in a rather large vacuole. 
During this history the androcyte becomes approximately spherical, 
then, as the bulk of the cytoplasm decreases, lenticular. A portion of the 
cytoplasm, including the limosphere, remains included within the curve of the 
posterior end of the mature antherozoid. 
The walls which originally separated the androcytes gradually soften 
and become dissolved. Each antherozoid, when mature, lies in a vesicle 
which, seen as the contents ooze out of the antheridium, seems to be bounded 
