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THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY. [V. I
if only a few males are taken into account, in the absence of the morphological charac-
ters of the females and their ova. Bhalerao [1932] by comparing in a tabular form
the range of variation of testicular glands in the different species, has suggested that
the number of testes is not important in the specific identity of schistosomes.
Secondly, he has pointed out that the caecum, a part of the alimentary canal of the
female, is variable in its nature and cannot be relied upon in aiding the specific
identification of these, hence it is evident that the alimentary canal of a male schis-
tosome may vary as much, if not more, because it is much more muscular than the
female. Bhalerao [1932, 1934] says that the nature of the cuticle and the average
size of the worm are not of any significance. By eliminating these four important
morphological characters as variable and therefore unreliable, there is nothing left
to compare the male schistosome in question with a male S. japonicum to say they
are identical.
Regarding the second point it is interesting to quote Faust and Meleney [1924]
who say that they have analysed all the numerous researches on schistosome cer-
cariae, and affirm that " although the cephalic glands have been at times inaccura-
tely and inadequately observed and described, they constitute, nevertheless, specific
characters by which definite differentiation of species may be made ". One of
us (M. A. N. R.), who has had many opportunities to study cercariae, agrees with
them regarding the importance of the characters presented by the cephalic glands.
Therefore, with this additional knowledge at the present moment about the cephalic
glands in schistosome cercariae, one cannot brush aside the morphological details
of these important glands, and still hold that those cercariae described by Sewell
[1919] are of S. japonicum. Further Sewell [1922] redescribed the same cercariae
under the heading Cercariae Indicae XXX, and Rao [1933] has definitely proved,
by experimental evidence, that those cercariae produce nasal schistosomiasis in
cattle. The identity of the adult schistosomes obtained from those cercariae has
also been settled by Rao [1934]. These schistosomes experimentally obtained
have been found to be similar to the ones described by Rao [1932] from the nasal
veins of naturally infected cases of nasal schistosomiasis. It would appear there-
fore that Bhalerao is not aware of these facts. The cercariae in question are not of
S. japonicum, but they are the larval forms of the nasal schistosome.
It will not be out of place here to quote Faust [1930] who says that " the species
of operculate amphibious snails, which S. japonicum utilises for the intra-molluscan
phase of its life cycle, are peculiar to certain areas in the far east and therefore
Schistosomiasis japonica is restricted in its distribution in accordance with the dis-
tribution of its molluscan host". The present writers were unable to find any
record, so far, reporting the existence of snails of the genus Onchomelania in India.
It is therefore suggested that the Schistosome of the pig in Calcutta described
by Bhalerao [1934] is not S. japonicum, but there are reasons to believe that it is
S. suis.