Allen . — The Spermatogenesis of Poly trichum juniperinum . 277 
chromatic constituents (including perhaps the nucleole, which is no longer 
recognizable) are pressed more closely together (Figs. 48, 49), and finally 
(Figs. 50-55) the body of the antherozoid, consisting of the nucleus 
intimately united with, and indistinguishable from, what remains of the 
blepharoplast, becomes a slender, coiled chromatic rod, somewhat slenderer 
or even pointed at its anterior and posterior ends. The exact degree of 
coiling of this body, and perhaps also its length, vary in different 
antherozoids (compare, e. g. Figs. 51 and 52) ; as a rule, the body 
constitutes about one and one-half coils of a spiral. 
While the nucleus is undergoing the changes just described, the body 
of the blepharoplast, except for the short portion at its anterior end, 
becomes indistinguishable. This is sometimes the case even in the very 
early stages of nuclear elongation (Figs. 25, PL XV ; 27, PI. XVI). However, 
in other cells at corresponding stages (Figs. 26, PI. XV ; 30 and 31, PL XVI), 
and even sometimes at a considerably later period (Figs. 32, 33, 35), the 
blepharoplast is still visible throughout its length. Indeed, in the cells 
shown in Figs. 32 and 35, the blepharoplast seems to be longer than it was 
seen to be at any earlier period, as though it had continued to grow in 
length after the change in shape of the nucleus had begun. Sometimes 
(Figs. 23, PL XV ; 29, PL XVI) the blepharoplast can be followed for some 
distance backward from the point at which the anterior end of the nucleus 
is applied to it, but it disappears before the posterior portion of the nucleus 
is reached. It seems probable that the difficulty in distinguishing the 
greater part of the body of the blepharoplast is due, not to an actual 
disappearance of part of its substance, but to some change which makes 
it less conspicuous. This might be a change merely in its staining 
reactions ; it might be in part due to a stretching of the blepharoplast 
after the nucleus has begun to elongate, with a resultant decrease in 
thickness ; or it might be because of an intimate union with, and flattening 
along, the nuclear membrane. The last explanation, however, would not 
account for the invisibility of the posterior part of the blepharoplast, with 
which, at such stages as those of Figs. 23 and 25 (PI. XV), no part of the 
nucleus is yet in contact ; and, on the whole, a change in the reactions 
of the blepharoplast to stains seems the most probable explanation of its 
apparent disappearance. This notion is strengthened by such cases as 
those shown in Figs. 28 and 29, PL XVI. In the androcyte represented in 
Fig. 28, the part of the blepharoplast that is in contact with the nucleus 
cannot be traced with any certainty ; but that part which extends posteriorly 
beyond the nucleus is visible, though faintly stained. In other androcytes 
in the same antheridium, the posterior portion of the blepharoplast is more 
conspicuous. Fig. 29 represents an androcyte found in another section 
of the same antheridium. In this cell the blepharoplast is plainly visible 
from its anterior end to about the middle of that part which touches the 
U 
