452 
Woodburn.—Spermatogenesis in 
Final Stages in the Development of the Sperm. 
It has been suggested in the previous paragraph that two structures, 
the blepharoplast and nucleus, unite in producing the band- or ribbon-like 
structure of the mature sperm, which becomes coiled in the cell cavity. 
The cytoplasmic area within the coiled portion may contain one or more 
vacuoles (Figs. 22, 23, and 28) or a vacuolate area (Figs. 21,25, 2( 5 , and 27); 
occasionally the cell may be free from vacuoles (Fig. 24). Surrounding the 
vacuoles material occurs which stains sometimes very much like the body 
of the sperm (Figs. 23 and 26) or more like cytoplasm (Figs. 21, 25, and 
27). In Fig. 27 around one vacuole there is located densely staining 
material, while the remainder of the vacuoles are surrounded by strands or 
layers of material staining faintly, much like cytoplasm. Probably chro¬ 
matin may, in greater or less quantities, be at times diffused into the 
cytoplasmic region? If such is the case, there does not appear to be 
any regular or constant structures formed from this diffused nuclear 
material. The blepharoplast is the only regular and constant formation in 
the cytoplasm. A study of the figures from Fig. 21 to Fig. 29 suggests 
very strongly that this material localized within the area surrounded by the 
coiled band is either consumed by, or incorporated within, the main body 
of the sperm. Fig. 30 represents the most mature condition observed, in 
which the sperm is beginning to stretch out and all indications of the formerly 
included vesicle have disappeared. The last traces of this vesicle may be 
observed on the inner surface of the sperm in Fig. 29, where a considerable 
portion does not present a smooth outline, but a surface roughened with 
granular material certainly remains of the material included in the vesicle 
of the preceding figures. 
While it was impossible, as already stated, to differentiate in the last 
stages of development between blepharoplast and nucleus as two distinct 
structures, as can be easily done in the Liverworts, yet a study of Figs. 13, 
14, 15, 21, and 24-30 suggests that they do remain distinct at least for 
a considerable length of time. It seems probable that the nuclear material 
is distributed, in some cases at least, along the entire length of the blepharo¬ 
plast. It may be also that there is a more intimate association between the 
blepharoplast and nucleus in the Musci than in the Hepaticae. In Fig. 19 
the blepharoplast is clearly seen projecting in both directions beyond 
the nucleus; in Fig. 15 it is extended as a sharply differentiated cord 
a distance beyond the posterior end of the nucleus. In Fig. 24 the ble¬ 
pharoplast with cilia attached projects beyond the anterior end of the 
nucleus, while in Figs. 25-30 one or both extremities of the sperm body are 
seen to be drawn out into slender, almost filiform, tips. 
Figs. 25-30 indicate the difficulty in determining the origin of the 
cilia and their attachment in the earlier stages of development. This 
