in the Lungs of a Sheep. 108 
more opake and interspersed with numerous white specks, while 
the other was semitransparent and resembled soft tubercle. The 
exterior of all the masses lay immediately underneath the serous 
membrane, and some of them penetrated the pulmonary tissue, 
which was otherwise healthy, for about a quarter of an inch. 
A thin section was placed beneath the microscope and examined 
by reflected light, when a great many little objects, probably the 
white specks just spoken of, resembling in colour and outline 
grains of pearl barley, were seen distributed through the sur- 
rounding tissue. But with the aid of transmitted hght and 
lenses of greater magnifying power (+-inch focus), a number of 
animalcules, such as represented in the annexed figure (Plate V.B 
fig. 1), were seen coiled up and imbedded in a brownish mass 
consisting of minute cells and granules. They were very abun- 
dant in the opake portion of the section, and were very closely 
aggregated together in spots probably corresponding to the specks, 
whereas in the intervening portions as well as in the surround- 
ing more transparent structure, comparatively few were to be 
found. On making our first observation each imdividual was 
inclosed in a transparent membrane, which upon a subsequent 
examination was proved to be the wall of the ovum. We after- 
wards found many that had escaped from this envelope lying free 
in the morbid substance. Some were in the form of the letter S, 
while others presented a more complex convolution. On scraping 
a small portion from one of the tumours and mixing it with a 
little water between two slips of glass, the animals were seen to 
greater advantage, and their position in the pellucid covering 
was better defined. On several occasions we saw the animal 
liberate itself from the membrane in which it was encased ; this 
was accomplished by the approximation of the head and tail, 
which were subsequently separated, and driven against the sides 
of the sae that had previously been elongated, with such force as 
to rupture it and so set the animal at liberty. In its movements, 
which were vermicular, the animal showed considerable activity. 
As it lay extended when quiescent the head appeared of a conical 
shape, and the tail presented a small, curved, flexible, fihform ap- 
pendage which was very characteristic (Pl. V. figs. 1, 2,3). The 
integuments being transparent the alimentary canal could be 
distinctly traced, commencing narrow at the head, enlarging 
somewhat and terminating near the tail. In some this canal was 
empty (fig. 2), and the parietes of the tube clearly defined. In 
others it was occupied with granular matter (fig. 3) having much 
the appearance of the substance with which they were surrounded; 
in some instances to such an extent as to fill completely the m- 
terior of the animal. 
These Entozoa resemble the Trichina spiralis found in mus- 
