6 9 
of degenerated and some few normal red blood cells and pigmented leucocytes. 
A cross section of a worm shows the intestine to be crowded with more or 
less well preserved erythrocytes and some pigment granules. The pigmented 
leucocytes appear in little rows extending towards and into the subperitoneal space. 
The mucous membrane, though distended, is intact. The iron reaction is easily 
obtained. 
Section oj two small nodules, lying close together on the surface oj the ileum. 
These cysts are entirely separated from one another. They have originated in 
the external muscular coat and have distended the subperitoneum. The larger one 
has invaded the whole thickness of the external and extends to the outer half of the 
internal muscular coat; the smaller one is limited to the outer fibres of the external 
muscular coat, and does not greatly distend the subperitoneum. The larger cyst 
contains the usual cells, the pigment granules are quite numerous, but few pigmented 
cells are seen. Two sections of a worm occur. The infiltration of the cyst wall is 
not extensive, and very few eosinophiles are present. The small cyst contains 
numerous polymorphonuclears and a few pigmented leucocytes; the erythrocytes are 
very hard to find. No section of a worm is seen. The cyst wall of the external 
side is necrotic and infiltrated with polymorphonuclears and small round cells ; on 
the internal or visceral side, the wall is densely infiltrated with large clumps of 
eosinophiles, some small lymphocytes, and a few pigment-containing cells. 
Cyst in the internal and external muscular coats. 
This cyst creates a bulging both on the inside and outside of the bowel. It is 
dumb-bell-shaped and involves the inner half of the external coat and the whole of 
the internal muscular coat; it is situated diagonally to the longitudinal axis of the 
bowel. The two broad bases are joined by a narrower part or funnel. A section 
of a worm is lying in the internal part. The contents consist of many pigmented 
leucocytes and a large number of erythrocytes and pigment granules. In the 
cavity of the cyst, in the internal muscular portion several very large giant cells 
containing pigment granules are present. The cyst walls, composed of muscular 
fibres, are extensively infiltrated by mononucleated leucocytes and granulation cells; 
the part in the internal coat contains several giant cells. The lymphatics to the 
subperitoneum contain many mononuclear pigmented leucocytes. The vessels in the 
intermuscular space are filled with mononuclear leucocytes and normal looking red 
blood cells. Some of the veins are compressed by the extensive infiltration. 
Cyst in the external muscular coat over a Peyer's -patch. 
The cyst extends through the whole of the external and part of the internal 
muscular coat; the infiltration is extensive and reaches as far as the submucosal 
space. The contents of the cyst are leucocytic, and do not present any unusual 
characters; no giant cells are seen. The walls are infiltrated by large mononuclears, 
some small lymphocytes, and a very few eosinophiles; the infiltration extends to the 
middle of the submucosa, but no cells have passed the muscularis mucosae. The 
epithelial cells of the mucous membrane are swollen, and many are slightly necrotic; 
the lymphoid tissue of the glands is congested and small mononucleated leucocytes 
are quite numerous. 
Other portions of the ileum which, apparently, contain a submucosal cyst, on 
microscopical examination, are found to consist of collections of small tumours 
which lie closely together, but are absolutely distinct. It is not unusual to find two 
or three small cysts in the submucosa and one, rarely two, in the internal muscular 
coat. It is quite common to find submucosal and external muscular cysts in the 
same piece of bowel, and these, by their invasion of other coats, closely approximate 
one another. On only one occasion have there been found cysts in each of the 
coats, viz., submucous, internal and external muscular coats. In this respect the 
cysts of the large intestine differ, as it is most common to find cysts situated in 
the different coats lying close to one another. 
