microns wide, according to Hill. Railliet states in his Traite that 
these eggs are 330 to 350 microns long by 8 microns wide, and these 
measurements have been copied by subsequent authors, but apparently 
the figures for length here have been multiplied as the result of a 
shifted decimal point due to a printer’s error or a lapsus of some sort. 
Hill states that the embryo is about 104 microns long, whereas Railliet 
states that it is 600 to 700 microns long, perhaps as the result of a 
lapsus similar to that in the case of the egg measurements. Gon- 
gylonema scutatum, the gullet worm of sheep and cattle, occurs in 
horses also, and has been collected by the writer from the horse at 
Bethesda, Maryland. Physocephalus sexalatus, one of the stomach 
worms of swine, has been reported from the ass by Seurat, but the 
Fig. 44. Strongylus vulgaris. Egg. Enlarged. From Winchester, 1892. 
description of his specimens does not agree in all respects with the 
description of P. sexalatus and it seems advisable to reserve judgment 
in regard to the occurrence of this worm in the horse for the present. 
Dioctaphyme renale (Fig. 12), the giant kidney worm of the dog, 
has been reported at least four times from the horse by various writers. 
In spite of the fact that the numerous strongyles in the large 
intestine of the horse constitute the most important group of worm 
parasites of the horse, there is an astonishing scarcity of figures of the 
eggs and of egg measurements. It is of great interest to note that the 
only figure of one of these strongyle eggs which has been found by 
the present writer is one published by the late Dr. J. F. Winchester 
thirty years ago. This egg (Fig. 44), like the remainder of Win¬ 
chester’s figures, is labeled Strongylus armatus, but the other figures 
are evidently figures of S. vulgaris, and the sizes he gives for the egg, 
92 microns long by 54 microns wide, appear to be correct for S. vulgaris. 
46 
