CURATIVE TREATMENT OF SURRA IN BOVINES                            217

that there is little evidence on record to show that any one of these can be utilized
with success in the diagnosis of cattle surra, it still remains to be unequivocally
established that the reactions obtained by these methods are not essentially group,
as opposed to specific, reactions. The diagnostic value of Adhesion Phenomenon
was repeatedly tested at Muktesar upon rats artificially infected with T. evansi,
but the results were found difficult to interpret. As to the Complement Fixa-
tion test, however, Randall [ 1934 ] records having employed this successfully in
detecting the infection in suspected horses in the Philippines, where T. evansi
is the only known pathogenic type of trypanosome—a fact which evidently largely
contributed to the deduction that the reaction obtained in these cases was not due
to a species of trypanosome other than T. evansi.

In view of the uncertainty of the results to be expected from these tests, it was
not considered worth while to employ them in the present trials, but to adhere to
the established methods of diagnosis, as will be described later in this paper.

THE CHEMOTHERAPY OF BOVINE SURRA : A RESUME OF THE LITERATURE

While, as would appear from what has been stated in the preceding section,
there is a concensus of opinion concerning the unreliability of the methods hitherto
used in the diagnosis of bovine surra, nevertheless, some workers would appear to
hold that a permanent recovery in this condition is possible, although their views
in this respect do not appear to be based on any extensive experimental data.
Thus, Doeve [1917] refers to complete recovery having occurred in bovines when
they were well fed and kept indoors, so that re-infection could not take place.
Again, Leger and Vienne [ 1919 ] quote Lingard as having stated that recovery is
the rule among cattle in India, infected with surra. Similarly, Broudin [ 1927 ]
mentions the occurrence of spontaneous recovery in bovines if conditions are
favourable.

Mesnil and Leger [ 1912 ] would appear to furnish somewhat more definite,
although indirect, information upon the possibility of rendering cattle permanently
free from surra. These authors quote Wryburg [ 1907 ] as having stated that
two zebus which had recovered from surra in Sumatra were immune for a period
which did not exceed two years, and Mesnil had previously [ 1910 ] recorded the
case of another bovine that retained its immunity against a Mauritius strain for a
period of more than two years. These observations would seem to imply that in
the case of a " cured " bovine, a relapse is not likely to occur within two years from
the date of its recovery, and one may assume that an animal that has not shown
signs of relapse during this period is not likely to do so during the rest of its
life.

Douwes [ 1923 ], in Java, claims to have effected complete cure with Naganol
in seven out of eleven buffaloes suffering from surra, the blood of all cured animals
remaining negative for surra trypanosomes " as long as they were under obser-
vation ". Each animal received a single intravenous injection of 3 or 5 grms. of