216
Prosthogonimus indicus in Indian Fowls
of its vitellaria which do not extend in front of the acetabulum. P. fuel¬
leborni differs from P. indicus in the much smaller size of the body (2.28×
1.17 mm.) and the anterior extent of vitellaria which do not reach even the
middle of acetabulum. P. longus-morbificans differs from the new species
in the relative size of the acetabulum, which is one and a half
times the size of the oral sucker, and the posterior extent of the cirrus
sac which reaches the acetabulum. From P. querquedulae our species can
be easily distinguished by the posterior extent of the cirrus sac, which stops
far in front of the acetabulum, the topography of gonads, length of excretory
bladder and the extent of vitellaria. In the size ratio of its suckers (oral
sucker 0.63 × 0.73; acetabulum 0.87 in diameter), extremely small
length of its oesophagus, posterior extent of cirrus sac, which reaches
the acetabulum, and the post-acetabular and the restricted extent of the vite-
llaria P. leei differs remarkably from the species described in this paper.
PROSTHOGONIMIASIS
This trematode disease, which is caused by the infestation with members
of the genus Prosthogonimus, offers a poultry problem of the highest magni-
tude specially in low-lying and water-logged areas. It occurs in a large number
of different species of birds and affects only the female. Amongst the domes-
tic birds the disease has been reported from fowls, turkeys, geese and ducks.
Though its effects have been observed for centuries by farmers in Europe, who
were well acquainted with the symptoms and had even associated them with
the extensive flights of dragonflies in certain seasons and in spite of the finding
of these flukes in small numbers in the oviducts of diseased birds, no patho-
logical significance, as has been the case with several other helminthic diseases,
was attached to the presence of these parasites. In 1920, Thienemann observ-
ed the correlation between the extensive flights of the dragonfly—Libellula
quadrimaculata and the production of soft-shelled eggs by domestic hens.
He, however, attributed the disease to the presence of some toxic substance
in the body of the dragonfly. In the following year Hieronymi and Szidat
definitely attributed the disease to the presence of flukes—P. pellucidus von
Linstow [Syn. P. intercalandus Szidat, 1921], in the oviduct and described,
in detail, its symptoms and pathology.
Subsequently several new species of the genus Prosthogonimus have
been described and a large number of cases of prosthogonimiasis have been
recorded. Szidat [1927], reports that during the spring of 1926 it was impos-
sible to obtain fresh eggs in the vicinity of Rossiten, East Prussia, owing to
the devastating effects of prosthogonimiasis, and if a hen harboured more than
forty or fifty parasites it usually died. The same author [Szidat, 1933], refers
to this trouble as the most important disease of the low-lands of the Northern
Hemisphere. Similar cases have been reported from various parts of Germany
by Rheinhardt [1922], Ariess [1922], Seegart [1923], Mass [1923], and others
and by de Blieck and van Heelsbergen, [1923], from Holland where P. pellu-
cidus has been found to be the cause. Panisset, [1924], reported similar cases
of the disease from France. Kotlan and Chandler [1925] discovered that a