March, 1950]
C.
K.
RAO
AND
R.
O.
BERRY
53
region. The results of this study are shown in Table I. The cytoplasmic cap is
noticeable on most of the sperm presenting varying degrees of development, being
most pronounced in the sperm from the testis and the head of the epididymis.
When viewed on flat, the sperm head in this species is found to be similar in
appearance to the goat sperm except that it is slightly narrower and smaller.
Development of motility
Our results in this species correspond to the results obtained with the ram and
goat sperm and do not require special mention. Sperm from the tail of the epididy-
mis exhibit maximal motility. The consistency of the material obtained from the
various parts of the reproductive tract is similar to that in the ram and goat.
DISCUSSION
In the ram, goat and Barbary sheep, the cytoplasmic drop is seen at three
different positions on the testicular sperm. In some sperm it completely surrounds
the posterior half of the sperm head and probably corresponds to the protoplasmic
cuff reported by Selivanova [1939]. Some sperm have the drop posterior to the
head and completely surrounding the neck, while other sperm have the drop as
a compact mass at the anterior end of the connecting piece, behind the neck. These
three types presumably represent successive stages in the development of the testi-
cular sperm.
There are also present in the testis two types of sperm which are
not ordinarily found in the ejaculate or in the lower part of the epididymis. To the
first class belong sperms which have a filiform connecting piece which may at times
also show a wavy condition. The second type of sperm have the connecting
piece of normal thickness but tortuous in appearance. These two types of sperm
are quite abundant in preparations from the testis and the former presumably
represents an earlier stage in the development of sperm.
In the head of the epididymis in all three species a great majority of the sperm
have the drop at the anterior end of the connecting piece, which is usually normal
in development and appearance. However, it is not unusual to find a few sperm
with a tortuous connecting piece. In the body of the epididymis this drop is located
at various levels on the connecting piece and in the tail of the epididymis it is usually
absent from a large number of sperm. The extrusion of the drop is probably
brought about by the active movement of the sperm in this region and the sperm
that still possesses the drop could not get rid of it due to the restricted movement
and partial clumping or sticking together of sperm. The descent of the drop seems to
be controlled largely by factors which are internal rather than external, owing to
the fact that sperm with posterior drops may be found in considerable numbers in
the head of the epididymis and sperm with anterior drops may occasionally be
present in large numbers in the body of the epididymis. It appears that the
cytoplasmic drop is associated with sperm maturation and presumably has a nutri-
tive function [Rao and Hart, 1948a], this being supported by the following facts :
(i) The filiform or tortuous connecting piece on the sperm is seen only when the
cytoplasmic drop is situated at the anterior end of the connecting
piece or higher up at the base of the head ; and (ii) the cytoplasmic drop is large