September, 1956]
A. K.
VARMA
105
The eggs
Different descriptions and measurements have been given by different authors for
the eggs of M. expansa and the illustrations furnished by them are so varying and
confusing that the laboratory man is often baffled. Baylis [1929] records that the
eggs measure 0.05 to 0.07 mm. in diameter and figures them as spherical in shape.
Bhalerao's [1935] measurements are 0.050-0.090 mm. for diameter and his text-
figure also indicates that they are spherical in shape. But, Monnig [1950] describes
them as somewhat triangular in shape, containing a well developed pyriform appara-
tus, and measuring 56-67 µ. in diameter.
In the present study the fresh eggs examined in a series of faecal samples by sugar
floatation method presented a different picture altogether. They were neither
spherical nor triangular but had rather a rhomboidal shape, the sides of which
measured 40-55 µ. and the diameter 50-65 µ. Instances of individual variations from
triangular to spherical shape were met with but very rarely. These are all illustra-
ted by furnishing camera lucida drawings [Fig. 2]. Examination of these eggs
in utero in stained preparations of the segments did not show any uniformity or
constancy in their morphology, as they were shrivelled up presenting spherical,
triangular or rhomboidal shape with irregular outline, and perhaps this accounts
for the variations in observations of the previous authors. Monnig's [loc. cit.]
figure of the egg of M. benedeni resembles more or less the eggs of M. expansa observed
by the author in the present study.
Pathogenicity
A good deal of controversy exists in the available literature over the pathogenicity
of this parasite and some authors believe that these worms are not harmful at all.
Monnig [1950], however, maintains that heavy infestations with this parasite are
common but even one or a few worms are able to produce disease.
Lafenetre [1948], while recording an epizootic of monieziasis in sheep in France
with losses ranging from 5 to 25 per cent, observed that although the infected animals
were in good condition, the death was sudden. Kates and Goldberg [1949 and 1951]
observed the contrary in America and found that lambs heavily infected experimentally
with M. expansa showed no clinical symptoms or any observable injurious effect and
that there was no significant retardation in growth or differences in weight. Hansen
Kelley and Todd [1950], however, noticed retardation in growth and some reduction
in the haemoglobin and the packed cell volume of erythrocytes, with loss in market-
able weight in lambs infected experimentally with M. expansa. Link and his
associates [1950] also supported that heavy infestation with M. expansa was
considered to be the cause of severe loss in a calf-herd in Illinois. Harries [1953]
found that in a sheep flock heavily infected with M. expansa, both the ewes and the
lambs were in poor condition and there was some mortality.
Infection of ruminants with this parasite, particularly lambs, kids and calves
is not uncommon in India. Bhalerao [1947] remarked that in India infection with
M. expansa was very heavy in some localities and caused considerable mortality
among livestock, particularly in ovines. He observed that the records of a sheep