March, 1958]
A.
G.
SATHYANESAN
19
substance. Such secretory acidophils are absent during the resting phase. The
presence of the secretory acidophils only in the regression period suggests the possi-
bility of their having some role in the repair of the gonads taking place during this
period. The probable significance of the presence of small basophils in the pars
nervosa in specimens collected soon after depletion of the gonads is not known.
The chromophobes in the ubergangsteil do not show any variation during the
pre-spawning and spawning phases. But in the post-spawning phase an increase in
the percentage is obvious.
The variations in the pars anterior and pars intermedia are not regular and well
defined. Hence these changes cannot be taken as seasonal with certainty.
Charipper [1937], Bell [1938], Levenstein [1939] and Potts [1942] have homo-
logized the ubergangsteil of teleosts to the pars anterior of higher vertebrates. The
existence of some structural and functional similarities between the ubergangsteil
of C. reba and the pars anterior of higher vertebrates is apparent.
SUMMARY
The morphology and seasonal changes occurring in the pituitary of C. reba are
described.
The ubergangsteil is the only glandular component exhibiting marked correlative
seasonal changes. The variations in the basophils of this lobe are pronounced. The
secretory activity of the acidophils is evident immediately after spawning. The
changes in the chromophobes are much less to suggest any prominent role.
The colloid like material in the pars nervosa presents apparent quantitative
variations during the different phases.
ACKNOWLEDGMENTS
The author thanks Dr P. Govindan, Reader in Zoology, for his assistance
throughout this investigation. He is also thankful to Professor R. V. Seshaiya for
providing facilities and to Shri K. Ranga Rajan for his encouragement. The author
expresses gratefulness to the Indian Council of Agricultural Research whose Piscicul-
tural Research Scheme made this work possible.
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