Two of the swine parasites of which the eggs were figured in the 
previous article in this series, namely, Arduenna strongylina and 
Physocephalus sexalatus, have recently been reported as accidental 
parasites of cattle in the United States by Dikinans, and another 
swine parasite, the kidney worm, Stephanurus dentatus, has been re¬ 
ported from cattle by Hall. The gullet worm of cattle, sheep and 
goats, occasionally present in horses, Gongylonema scutatum, has an 
egg (Fig. 33) 56 to 60 microns long by 32 to 36 microns wide, con¬ 
taining at the time of oviposition an embryo provided with a hook-like 
process on one side near the anterior end, the opposite side of the 
anterior end of the worm showing an annulate marking. The eggs 
Fig. 35. Haemonchus contortus. Eggs in various stages of development, x 380. 
From Veglia, 1916. 
of another gullet worm, G. verrucosum of sheep and goats, are 45 to 
50 microns long by 25 to 27 microns wide. The eggs of the cattle 
ascarid, Ascaris vitulorum, are 75 to 80 microns in diameter. The 
ascarids found in sheep appear to be specimens of Ascaris lumbricoides 
of man and swine, present as accidental parasites in an unusual host 
and quite generally incompletely developed and devoid of eggs, or at 
least of fertile eggs. 
The eggs of the numerous strongyles occurring in the digestive 
tract of ruminants are commonly more or less elliptical and thin- 
shelled. Although the egg sizes overlap in many cases to such an 
extent that it is often impossible to determine the species present, a 
reasonable probability as to the presence of certain worms may be 
38 
