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ABSTRACTS
[Vol. XXIV, Part I,
cases a large number of trypanosomes, mostly in a state of lysis, was found in the
smears of kidney, heart, etc.
It is a well-known fact that drugs including Antrycide are ineffective in destroy-
ing trypanosomes in vitro in concentrations effective in the living body. The drugs
might not act as prophylactics in the sense that they would prevent a temporary
lodgement of parasities in the body. Various experiments regarding the drug
fastness of the trypanosomes (especially T. vivax and T. congolense) with Antrycide
and Dimidium were also studied. Treatment with Antrycide sulphate did not affect
the number of cattle showing positive blood smears (Dose. Antrycide, 0.2 to 0.5
mg/kg.; Dimidium ; 1 to 2 mg/kg.). When treated subsequently with dimidium
bromide, trypanosomes were removed from the circulating blood but deaths were
not arrested. The strains of T. congolense, isolated from cattle which had become
infected following protection with Antrycide or Dimidium under natural conditions,
were resistant to one or both drugs.
The protective property of Antrycide was also studied. It was found that
Antrycide prosalt (Dose 4 mg/kg.), a mixture of sulphate and chloride, gave uni-
formly good results; while no other preparation or mixture of preparations was
reliable. In both, the normal as well as protected mice, most of the injected try-
panosomes were destroyed but small number survived as a focus of infection.
A few parasites were always found in the peritoneal cavity or in tissue smears,
especially those of lung, liver and kidney. There was no difference between the
control and treated mice. The same experiment was repeated with a higher dose of
Antrycide (Dose 12 mg/kg.). Only a small proportion of T. congolense was able to
survive. There was absolutely no difference between those which received large doses
of Antrycide and those which did not.
The anaemic condition in trypanosomiasis was also studied. In acute stages,
there was a fall of red cell count and haemoglobin estimation. As the anaemia
progressed, the red cell size and haemoglobin percentage decreased. As the crisis
approached there was anisocytosis, polychromasia, punctate basophilia and hypo-
chromia. In chronic stages, there is a tendency of the red cell count to recover and
low haemoglobin percentage. There is microcytic anaemia. In cryptic stage, the
picture is just like in chronic stage. The blood picture in normal cattle which was
given monthly injections of Antrycide did not show anything abnormal. The text
has been illustrated with four excellent charts. (V.V.S.)
Evidence of gene-controlled sterility in bulls. H. P. DONALD AND J. L. HANCOCK.
(1953), J. agri. Sci. 43, 2, 178-181
A SPERMATOZOAL defect characterised by an abnormal formation of the
acrosome was observed in 17 sterile Friesian bulls over a period of
six years. The affected spermatozoa are referred to in this paper as 'Knobbed'.
The defect was identified by microscopical examination of semen smears stained
with Indian ink or Giemsa. Of the 17 bulls, eleven were bred and reared in one
herd, three in another and one in each of three more herds. All the bulls, with one
exception, were related to three common ancestors. Coefficients of inbreeding varied
from 0 to 25. It is concluded that the characteristic defect of the acrosome is due
to an autosomal sex-linked recessive gene (kn.). (S.N.L.)