in diameter. The egg of A. mamillana is 50 to 60 microns in diameter 
according to some writers; Fiebiger states that it is oblong. 
Of the flukes infesting the horse, Fasciola hepatica, Fascioloides 
magna and Dicrocoelium dendriticum have already been considered 
in previous papers. In India the horse is infested with a blood fluke, 
Schistosoma indicum, the eggs passing in the manure and in the urine. 
The egg (Fig. 41) is oval, with a spine at one end. In the fluke these 
eggs are from 92 to 100 microns, rarely 112 microns, long by 42 to 
44 microns, rarely 52 microns, wide, with a spine 13 to 14 microns 
long; eggs from the rectum of horses are 120 to 140 microns, rarely 
152 microns, long by 68 to 72 microns wide. The remaining flukes 
reported from horses are mostly amphistomes, flukes having an oral 
Fig. 42. Gastrodiscus aegyptiacus. Eggs, x 100. From Railliet, 1893. 
sucker at the anterior end and having the ventral sucker or acetabulum 
at the posterior end. Of these, Gastrodiscus aegyptiacus has ovoid 
eggs (Fig. 42) 150 to 170 microns long by 90 to 95 microns wide, ac¬ 
cording to some writers, or 170 to 190 microns long by 110 microns 
wide, according to Looss. The eggs of G. secundus are 150 to 160 
microns long by 90 to 100 microns wide. The eggs of Pseudodiscus 
collinsi and Ps. stanleyi do not appear to have been observed as yet. 
There are numerous nematodes infesting the horse. Among these 
is a species of Strongyloides, S. westeri, which is so far reported only 
from Holland. The life history of this worm is similar to those of 
species of Strongyloides referred to in previous papers; the eggs hatch 
44 
