Oct. io, 1913 
Cysticercus Ovis 
29 
lum prominent, 275 to 375/x in diameter. Hooks (fig. 6) 24 to 36 in number, commonly 
28 to 32, arranged in a double crown of alternating large and small hooks. Hooks 
rather slender (more slender and more lightly built than those of Cysticercus cellulosae ); 
dorsal root of large hooks longer than the blade; in both 
large and small hooks a more or less well-marked outward 
curving of the dorsal border of the hook in the transitional 
region between the blade and dorsal root; ventral root of 
small hooks transversely enlarged, not bifid but sometimes 
presenting a faint median groove. Large hooks 156 to 188/t 
long, average 173/4; blade (from point of blade to tip of 
ventral root measuring in a straight line) 68 to 84/4, average 
78/i (based on measurements of 24 hooks, fully developed 
or nearly so, from 10 cysticerci taken from various sheep 
and 13 hooks from the heads of 4 adult worms). Small 
hooks 96 to 128 )<1 long, average 113/4; blade (from point of 
blade to tip of ventral root measuring in a straight line) 48 
to 60 jjl, average 57/4 (based on measurements of 26 hooks, fully developed or nearly so, 
from 11 cysticerci taken from various sheep and 10 hooks from the heads of 4 adult 
worms). 1 
Calcareous corpuscles numerous in the neck, less numerous in the head, and very 
rare in the caudal bladder. 
Adult stage (PI. II,fig.3; text figs. 7,8,9,and 10).—Length of living worms with gravid 
segments, 45 to no cm. Length (preserved material), 14 to 53 cm.; maximum width, 
4 to 8.5 mm.; terminal segments, 2.5 to 15 mm. long by 4 to 6 mm. broad, usually 
longer than broad (measurements of 17 specimens with gravid segments). Strobila 
tends to twist in the form of a spiral. Head 0.8 to 1.25 mm. in breadth; neck, 0.65 
to 0.9 mm. wide (measurements of 26 preserved specimens). Rostellum 375 to 430/4 
in diameter (8 specimens). Suckers 2 70 to 320/4 in diameter (4 specimens). Number, 
arrangement, shape, and size of hooks as in larva. Segments with convex lateral 
borders, in consequence of which the edge of the strobila commonly presents a scal¬ 
loped outline whose regularity is broken by the protuberant genital papillae. The 
genital papillae are irregularly alternate and are situated posterior of the middle of the 
segment; in gravid segments they may attain a diameter of over 1 mm. and a height 
of three-fourths of a mm. Genital sinus large, varying in depth and width up to a 
maximum of about 400/1. Cirrus pouch 450 to 550/4 long; inner end near the outer 
side of the ventral longitudinal excretory vessel. The testicles are distributed in an 
area which extends anteriorly to the anterior limits of the segment and laterally to the 
longitudinal excretory vessels. This area is bounded posteriorly by a curved line 
which in sexually mature segments intersects the median line at a distance from the 
anterior border of the segment varying from a little more than a third to a little less 
than half the length of the segment and intersects the longitudinal excretory vessels 
a short distance in front of the posterior border of the segment, 4 hus leaving an approxi¬ 
mately semicircular space entirely free from testicles, most of which is occupied by 
the ovary. Behind the latter is the so-called yolk gland. The ovary is bilobed, the 
1 Measurements of 26 hooks. 
Member. 
Larva. 
Adult. 
Member. 
Larva. 
Adult. 
Large hooks: 
Entire. 
Average. 
Blade. 
it. - 
156 to 188 
173 
76 to 80 
79 
| 
It. 
160 to 184 
i 73 
68 to 84 
75 j 
Small hooks: 
Entire. 
Average. 
Blade. 
H- 
96 to 120 
112 
52 to 60 
57 
/*. 
104 to 128 
116 
48 to 60 
57 
Average. 
Average. 
Fig. 5.— Cysticercus ovipariens 
(=C. ovis): Papillae on caudal 
bladder, X 160. (After Mad¬ 
dox, 1873a, pi. 18, fig. 15.) 
