90 
Ascaris vitulorum Goeze 
Female. Tail short, the distance between the anus and the posterior 
extremity varies considerably in different specimens, from 0*6 to 1-1 mm. 
(Text-fig. 3). 
Vulva situated anteriorly, 25-30 mm. from the cephalic extremity and 
dividing the total length of the body in the proportion 1 : 8. Internal female 
organs as described by Neumann; the uteri are fused posteriorly, forming a 
common tube continuous with the vagina, the latter has a length of about 
10 mm., the total length of the unpaired genital duct measuring 30 mm. 
Fig. 3. Ascaris vitulorum. Posterior extremity of female, showing 
variation in length of caudal region, an. anus, x 35. 
Paired uteri short, about 70 mm. in length, running backwards, parallel with 
one another; each oviduct bears a conspicuous swelling or ampulla close to 
its junction with the uterus. 
Eggs 0-08-0-095 mm. long x 0-07-0-075 mm. wide, less coarsely mamillated 
than those of A. lumbricoides. 
The character of the oesophagus in A. vitulorum is of considerable interest 
from the systematic point of view; recent authorities, e.g. Railliet and Henry 
(1912) and Baylis (1920), have attached great importance to the structure 
