PTERIDOPHYTA. 131 
Belajeff (’98). Prior to the division of the grandmother-cell of the 
spermatozoid, 7. e., the last cell-division in the spermogenous tissue 
of the antheridium, which gives rise to the cells that develop directly 
into the spermatozoids, there appears on opposite sides of the nucleus 
a small globular body of a homogeneous structure, staining rather 
densely (Fig. 51, A). These bodies are not provided with any radia- 
tions. In Oxoclea there is, immediately surrounding the nucleus, a 
region of less granular cytoplasm from which, undoubtedly, the weft 
of spindle fibers is developed. These bodies, which are the primordia 
of the blepharoplasts, lie just at the outer edge of this region or weft 
(Fig. 51, A). In the telophase a blepharoplast primordium lies near 
the depression of each daughter-nucleus, very near the pole of the 
spindle (Fig. 51, B, C). Each appears now to be a hollow globular 
vesicle. Soon after cell-division is completed the development of the 
daughter-cells directly into spermatozoids begins. The blepharoplast 
primordium becomes somewhat lens- or crescent-shape in Gymmno- 
gramme, with the concave side turned toward the nucleus. The 
nucleus at the same time becomes flattened upon one side and gradu- 
ally passes into a crescent- or pear-shaped body (Fig. 51, D, E). The 
blepharoplast has elongated into a thread or band, which follows the 
convex side of the nucleus and is rather close to it. Oneend of the band 
now extends beyond that end of the nucleus which will be anterior in 
the mature spermatozoid (Fig. 51, F, G). With further development 
the blepharoplast moves away from the nucleus to a position just 
beneath the plasma membrane (Fig. 51, H). At this stage the cyto- 
plasm in Oxoclea (Shaw, ’98) shows a depression corresponding to the 
concave side of the nucleus. At about this period in the development 
in Gymnogramme, according to Belajeff, the cilia make their appear- 
ance as outgrowths of the blepharoplast. The nucleus elongates, 
becoming more slender, and gradually assuming a spiral or corkscrew 
shape of two or three turns. In the mature spermatozoid (Fig. 52, 
A) the nucleus is thicker, tapering abruptly, and sometimes to a point, 
at the posterior end, but gradually forward into a slender anterior end. 
It is oval in cross section, or, in some cases, slightly flattened on the 
inner side, especially in the thicker posterior part. In mature sperma- 
tozoids of Oxoclea struthiopteris, fixed and stained on the slide, the 
cytoplasmic part seems to be in the form of a band which conforms to 
the spiral course of the nucleus. It is broadest at the anterior end, 
which extends a short distance, about one or two turns, beyond the 
anterior end of the nucleus, but it narrows gradually backward, dis- 
appearing at a point which marks the thickest part of the nucleus 
