DR. T. S. COBBOLD, FURTHER OBSERVATIONS ON ENTOZOA. 
355 
the external chitinous capsule presents the same characters as in T. dispttr; at either 
pole of the egg, where the shell terminates abruptly, an inner transparent membrane 
projects, in the form of a mammillary process (fig. 15). None of the eggs I examined 
appeared to contain fully developed embryos, but the interior yolk-mass exhibited evi- 
dences of segmentation, many of them displaying two nuclei. These ova have a longi- 
tudinal diameter of 3-^0 th to 3-^oth of an inch. 
Fig. 2 
a 
Fig. 1. 
Fie. 3. 
Figs. 1, 2, 3. 
/ 
KJ * 9 — J J T 9 ' 9 — W w ~ W " 
mittent muscle surrounding g, the sheath of the penis ; g\ infundibuliform portion ; g", exserted portion, armed 
with minute retroverted spines ; g'", flask or cup-shaped expansion of the free extremity of the sheath ; h, rings 
formed by contraction of a portion of the sheath ; i, penis ; i", infundibuliform upper extremity of the penis 
or spicule ; i'", free pointed end of the same ; k, an oval granular mass in one of the flask-shaped expansions, 
apparently consisting of spermatic particles ; I, cloacal cavity ; iff, anus. Drawn, with the aid of a camera, from 
specimens mounted and preserved in glycerine. 
In regard to the solution of Kuchenmeister's hypothesis, which assumes the encysted 
Trichina to be only immature forms of the more highly developed Trichocephalus, my 
experiments have again been attended with merely negative results ; but this has possibly 
arisen more from the unsuitableness of the particular hosts selected and operated on, 
from any other 
Prom economical considerations, I confess to have refrained 
from experimenting on sheep and pigs 
On the 8th of December, 1859, I fed a rabbit 
ith portions of raw potato, on which were placed three fresh female Trichocephali, all 
of them being readily devoured. On the 13th January following the rabbit was destroyed, 
and carefully examined, when neither Trichina nor eggs of Trichocephalus could be 
detected. On the day above mentioned I also fed a chicken with three other fresh Tri- 
chocephali ; these worms having all been previously obtained from the giraffe. The bird 
perished from exposure to severe cold 
the sixth night succeeding the experiment 
Wh 
however, I dissected it several days afterwards, although the muscles showed 
I 
to 
extent gratified to find several egg-shells of the 
cephali still lodged in the intestinal 
Most of the egg-capsules were empty ; but 
few of them exhibited thinly scattered and disintegrated 
Since the above was written, I observe that Leuckart's 
that 
the young of Trichocephalus. See his treatise entitled 
tom.xiii. p. 318. 
VOL. XXIII 
Wiirmk rankheiten 
Untersuchungen iiber Trichina spiralis, zugleich in Beitrag 
Hplh Pr? . 1860. See also ' Ann. des Sci. Nat.,' 4me ser. 
3 
