38 
Journal of Agricultural Research 
Vol. I, No i. 
between T . ovis and 7 \ krabbei is apparent in the gravid uterus. Instead 
of the 20 to 30 lateral branches seen in T . ovis there are in T, krabbei 
only about 10 lateral branches from each side of the median stem. It 
is quite clear from the brief study which has been made of the type 
material of T. krabbei that it is specifically distinct from T . ovis , although 
the similarity between the two species is very close in many respects. 
MACROSCOPIC APPEARANCE OF CYSTICERCUS OVIS 
The cyst of the fully developed undegenerated cysticeicus as seen 
embedded in the muscles of its host is oval and varies in size from 4 by 2.5 
mm. to 9 by 4 mm. or slightly larger (PI. Ill, A and B ). It is whitish in 
color and varies in transparency according to the thickness of its fibrous 
capsule, which may be very thin and rather transparent or comparatively 
thick and rather opaque. In transparent cysts 
the head and neck of the cysticercus are apparent 
as a small, bright, white spot showing through 
the wall of the cyst. Removed from its cyst the 
cysticercus (PL II, fig. 1) appears as a small 
oval vesicle very transparent and delicate, filled 
with a clear fluid, and varying in size when fully 
developed from 3.5 by 2 mm. to 9 by 4 mm. On 
one side may be seen the opaque white head and 
neck invaginated into the vesicle or quite com¬ 
monly partially evaginated and then projecting 
above the surface of the vesicle. Cysticercus 
ovis is more delicate in appearance and averages 
in size smaller than C. cellulosae. It is considerably smaller than a fully 
developed C. ienuicollis. 
Degenerate cysts (fig. 13, b t and Pis. Ill, fig. E, and IV, fig. 2) vary in 
size, shape, thickness of capsule, and consistency and color of contents. The 
sizes of 50 degenerate cysts taken at random varied from 3.5 to 15 mm. 
in diameter; 7 by 4 mm. was a common size. Different authors have 
observed cysts varying in size from that of a millet seed to that of a bean. 
The shape is commonly oval or spheroidal, but may exhibit various 
irregularities. 
The fibrous capsule of the degenerate cyst may be quite thin or relatively 
very thick. For example, the capsule of a cyst from the masseter muscle, 
measuring 7 by 4 mm., was about one-third of a millimeter thick; another 
cyst, 5 by 2.5 mm. in diameter, from the same muscle had a capsule about 
three-fourths of a millimeter thick; a cyst 10 by 7 mm. from the heart had 
a capsule 3 mm. thick; and the capsule of another cyst, 8 by 6 mm. in 
diameter, also from the heart, measured one-third of a millimeter in 
thickness. The cavity of the cyst is commonly irregular in shape and 
contains besides the cysticercus a mass of caseous, caseo-calcareous, or 
calcareous material, or sometimes an albuminous coagulum or a soft 
purulent substance. The color of the contents may be white, yellowish, 
Fig. 13. —Cysticercus ovipariens (= 
C. Ovis): a, Hook,Xi6o; b, cyst 
containing cysticercus cut across, 
X2. (After Maddox, 1873a, pi. 
18 fig. 1.) 
