Spermatophoric Mass of a Nephropsid — MATTHEWS 
117 
in thickness and consists of longitudinal, di- 
agonal, and circular fibers. 
Fig. 3. Camera lucida drawing of a cross section 
through a follicle in the early stages of maturity show- 
ing; a, spermatids; h, primary spermatocytes; c, nuclei 
of sustentacular cells; d, meiotic figures of spermatid 
formation. (175 X) 
DISCUSSION 
By mitotic division of the germinal epithe- 
lial cells (Fig. 2d), follicles fill with primary 
spermatocytes (c). During this process, cer- 
tain cells with strongly chromatophilic nuclei 
ih) apparently arise from the germinal epi- 
thelial cells and occupy positions between the 
primary spermatocytes (c). Although mitotic 
figures are associated with the increase of pri- 
mary spermatocytes, no mitotic figures ac- 
company the increase of the strongly chro- 
matophilic cells. Their method of multiplica- 
tion remains obscure. 
Concurrently, the primary spermatocytes 
(Fig. 3^) by two successive divisions {d) give 
the tubule surrounds each group of sperma- 
tozoa. 
Cross sections of the minute, proximal por- 
tion of the vas deferens (Fig. 5) reveal a tube 
in which the sperm mass {a) is surrounded 
by columnar epithelium {Id) and a muscular 
layer (c). Although the columnar epithelial 
cells appear active, there is no evidence, in 
this region of the vas deferens, that a sheath 
is being formed around the sperm mass. 
A portion of a cross section of the vas 
deferens (Fig. 6) (distad to the portion illus- 
trated in Fig. 5) shows the sperm mass {a) 
enveloped by a spermatophoric sheath {h) and 
that this sheath is the product of the secretion 
from the epithelial cells (c). The thickness of 
the muscular layer {d) is only slightly in- 
creased over that illustrated in Figure 5. 
Figure 7 illustrates a portion of a cross 
section through the distal region of the vas 
deferens. The sperm mass {d) is not only 
enveloped by a spermatophoric sheath {h), 
but a homogeneous matrix (c) is added by 
the epithelial cells {e) . The matrix (c) is often 
separated from the epithelial cells {e) by a 
space {d ) . The muscular layer (/) is increased 
Fig. 4. Camera lucida drawing of cross section 
through mature follicles discharging their contents into 
the collecting tubule showing: a, spermatozoa; b, pri- 
mary spermatocytes; c, longitudinal section of collect- 
ing tubule; d, groups of spermatozoa ejected from 
different follicles; e, contents of a single follicle being 
ejected into collecting tubule; /, secretion separating 
sperm groups; g, epithelial cells. (150X) 
