A STUDY OF THE LIFE-HISTORY AND PATHOGENICITY
    OF COTYLOPHORON COTYLOPHORUM (FISCHOEDER,
      1901) STILES AND GOLDBERGER, 1910, OF INDIAN
            RUMINANTS AND A BIOLOGICAL CONTROL
                         TO CHECK THE INFESTATION

                                              BY

                        HAR DAYAL SRIVASTAVA, D.Sc.

                          Helminthologist (On special duty)

        Imperial Veterinary Research Institute, Mukteswar-Kumaun

                  (Received for publication on 23rd March 1938)

                              (With Plates XXXI—XXXIV)

THOUGH a knowledge of the life-history of a parasite is necessary in de-
termining its pathogenicity and in devising means to check its infestation,
the life-histories of only a few trematodes have so far been worked out in this
country. Liston and Soparkar [1917] carried out experiments on the life-
history of Schistosoma spindalis and found that snails of the species Indoplan-
orbis exustus and Limnaea acuminata serve as the intermediate hosts. Rao and
Ayyar [1932] discovered the molluscan hosts of two amphistomes— Param-
phistomum cervi and Fischoederius elongatus. A year later Rao established the
life-cycle of Schistosoma nasalis. Bhalerao in 1933 demonstrated that L.
acuminata serves as the intermediate host of Fasciola gigantica in the Kumaun
hills.

The occurrence of epizootics of acute amphistomiasis among sheep
and goats in the United Provinces was responsible for undertaking an investi-
gation into the life-history of a common amphistome, Cotylophoron cotylopho-
rum, of Indian ruminants. Besides establishing experimentally the life-
history and the pathogenicity of the amphistome, a biological control to check
its infestation has been discovered. It has been observed that while adult
amphistomes are apparently non-pathogenic, they are, in their immature
stages, highly pathogenic.

Specifically determined adult specimens of the amphistome, obtained from
the rumen of goats and sheep, were first thoroughly washed with water and
then placed in small beakers containing normal saline and were kept at body
temperature in an incubator. When a sufficient number of eggs was laid, the
worms, while they were still alive, were removed and the saline was decanted.
The eggs were washed in several changes of water. It was found that any
bacterial growth in the beaker containing eggs interfered with their develop-
ment. The eggs were kept in distilled water which was changed at least thrice

                                                (381)

                                                                                                               Q.