32 THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [ III, I
Histopathology.—The nasal growths of animals from different parts of the
Presidency were available for study. Sections, usually serial, were stained with
haematoxylin and eosin for this study. In the sections thus stained, one's
attention is drawn to pink stained " Actino " bodies with a central core which may
be circular, oval, spindle shaped or crinkled. This body is surrounded by zones of
tissue cells and very often some cells are seen in between the streamers or rays of
this body. The central core is found to be a section of a schistosome ovum with
the contained miracidium. The appearance of such focus will necessarily vary as
to whether the section passes directly or not through the ovum. If the section
just misses the end of the ovum, only a pink mass with no core will be seen. This
pink mass is only the " actino " body and resembles markedly a granule of Strepto¬
thrix. The whole area round about the ovum simulates a Bilharzial Pseudo-tuber-
cle designated by Fairley [1920]. In some sections. in a dilated vein or veins
one or more sections of schistosomes are seen (PI. IX, fig. 1). Such veins
usually show cellular zones of varying thickness round them. Very often some
of the blood vessels could not be recognised as such owing to changes in the walls.
The sections of schistosome are usually found deep down near the mucus glands.
Almost all the blood vessels in the sections appeared to be in a dilated condition
and in some of the larger blood vessels clots of blood with or without organisation
could be seen. Sometimes, an abscess containing the remnants of what appeared
to be a dead worm is met with. It is therefore evident that the inflammatory
reaction is due to the presence of worms and to a great extent it is probably due
to the toxic substance derived from the miracidia present in the large number of
ova in the tissue. These ova are found either in the capillaries, where they were
deposited by the female worm or in the tissue outside where they gained entrance.
The ova may be encountered in places anywhere between the situation of the
worms and the periphery of the growth. These ova found in the deeper layers of
the lesion did not usually show a fully formed miracidium, but those nearer the
periphery always did so. The former are perhaps freshly laid eggs. This coincides
with the view of Fairley and Mackie [1930] that the maturity of the miracidia
occurs only after the deposition of the ova in the tissue of the animal. The study
of sections leads one to believe that the ova of schistosomes, in the nasal growths,
depend on two factors for their migration to the exterior, viz., the distance of the
ovum from the free surface, and secondly on the quality of the toxic substance
discharged by the contained miracidium to bring about the necessary reaction
in the tissues to form an abscess, which may eventually burst on a free surface.
Otherwise the egg should ultimately get enclosed in fibrous tissue to become a
small bilharzial nodule only to get calcified eventually. Such nodules containing
one or more dead ova are occasionally met with in sections, particularly in growths