45 i 
Mnium affine , var. ciliaris ( Grev .), C.M. 
Quite an open network of cytoplasm is still present. Cross-sections of the 
blepharoplastic and nuclear band are here obtained. In Figs. 17 and 18 
the cross-section of this band forms a rather flat ellipse quite dense in con¬ 
tents throughout. Fig. 19 represents a very thin section through a cell 
where the nucleus is certainly well distributed into or along the blepharoplast, 
the two forming a common cord or band. As the section passes through 
this band four times it has evidently completed more than one full turn and 
a half. Three sections of the band are elliptical in outline and densely 
granular ; the fourth section is more circular in outline and hollow, indicat¬ 
ing that at this point, which may have been near the middle, the structure 
in question was tubular. The two sections of the band which are shown in 
Fig. 20 are both nearly circular and more or less hollow, indicating here also 
a tubular structure. The vacuole noted elsewhere is shown to lie, sometimes 
at least, to one side of the nuclear band (Fig. 20). The fact that the body 
of the sperm as first formed is often tubular or vacuolate through the centre, 
helps no doubt to explain the process whereby this structure lengthens and 
grows less in diameter. A section passing in a somewhat obliquely 
horizontal plane through such a cell as is shown in Fig. 16 might very 
readily make three cross-sections of the nuclear band, and the appearance 
of this figure in side-view would suggest the probability that one section 
would be vacuolate in the centre and the other two more nearly homo¬ 
geneously granular throughout. (Compare such an imaginary cross-section 
with Fig. 19.) 
Summing up briefly conclusions in regard to the nature and develop¬ 
ment of the blepharoplast, as suggested by an observation of Figs. 10-33, 
we find that a darkly staining granule or body, apparently a cytoplasmic 
differentiation, develops into a more or less radially flattened band along the 
edge of the cell in contact with the plasma membrane. This band, which 
we will call the blepharoplast, is at first situated independently of the 
nucleus, but the two soon come into close contact and finally seem to 
be fused into one homogeneously staining band. The original blepharo¬ 
plastic band remains more densely staining in capacity for some time, though 
of apparently the same staining affinities (Fig. 31). This band, consisting 
of nucleus and blepharoplast, now forms the main body of the sperm, 
and cross-sections show that it is more or less radially flattened, at least 
towards the two ends, and in earlier stages a vacuole passes for some 
distance through the centre, making the structure more or less tubular, 
at least throughout part of its length. There is a very close association 
between the nucleus and blepharoplast, with probably some question as 
to whether these two bodies remain as distinct parts or become, to a certain 
extent at least, a homogeneous structure. 
