73 
the cyst walls were not attacked so long as the muscular is mucosae remained intact. 
In one case the necrosis affected the outer half of the adjacent cyst wall. 
Examination of the extensive black patches occurring in the wall of the gut has 
been unsatisfactory. Some of the patches are situated in the submucosa, others are 
in the subperitoneal space. The patches are caused by extravasated blood, and many 
well-preserved erythrocytes are still present; much blood pigment has been soaked 
up by the surrounding tissues, while only a moderate number of macrophages 
contain pigment. One or two patches in the subperitoneum, in the vicinity of cysts 
were invaded by large giant cells, many of which contained pigment. Evidences of 
repair were present in all the extensive areas. Iron pigment was rarely 
demonstrable. No traces of oesophagostome larvae or ova have been found. 
Appendix vermijormis. Sub -peritoneal tumour, sectioned transversely. 
This large cyst has developed in the subperitoneal space of the wall of the 
appendix, and from there has extended outwards into a cyst-mass larger than the 
appendix. The external muscular coat of the appendix is not involved. Between 
the external muscular coat and the tumour, the large blood vessels are seen cut 
across ; these are filled with red blood cells and some leucocytes. Other blood vessels 
follow the peritoneal fascia along the tumour wall, penetrating to the interior of the 
cyst. The walls of the cyst consist of well organized connective tissue, and from the 
main walls thick strands cross the cavity and divide it into two main parts. A 
study of serial sections proves that the cyst tumour consists of an internal or 
proximal and an external or distal cyst. They are separated by the main divisional 
wall, which is continued completely across, from the upper to the lower walls of the 
tumour. These cysts are subdivided into small chambers by incomplete side walls 
of connective tissue. In one of the chambers of the distal cyst two transverse 
sections of a worm are seen; in other slides longitudinal sections of the cephalic end 
of the worm are found in the larger chamber of the external cyst. The serial 
sections show that the proximal cyst contains no worm. 
The contents of the cyst are mainly leucocytes and red cells. Great numbers of 
polymorphonuclears are present in the cyst chambers, and the partition walls are 
infiltrated by mononuclears. 
Higher magnification. The contents are nearly all pus cells with a few 
well-preserved and many degenerated erythrocytes, a few mononuclears, free 
pigment, and granular d6bris. The outer walls of the proximal cyst are 
lined with well-preserved pavement epithelium. The connective tissue is 
infiltrated by masses of mononuclears and some small round cells. Very few 
eosinophiles are seen. The blood vessels are large, and the veins are filled with 
many polymorphonuclear and mononuclear leucocytes, and well preserved 
erythrocytes. No bacilli or cocci are to be found. The sections of the worm show 
that the intestine contains some normal-looking and degenerated red blood cells. 
Large pigmented cells are found in the proximal cyst, and a few giant cells are in 
the wall. 
The spleen sections show a very marked hyperplasia of the connective tissue of 
the capsule in which are numerous capillaries full of erythrocytes and some 
mcnonucleated leucocytes; in places the fibres are undergoing hyaline degeneration. 
The fibres of the upper strata are infiltrated with mononuclear and polymorphonu¬ 
clear leucocytes; the lower strata of the fibrous mass is not so much infiltrated. 
Golden brown to black pigment is scattered throughout the spleen in small and 
large clumps. It is especially marked about the blood vessels in the trabeculae and 
in the centre of the follicles. Many lymphoid cells appear to be degenerated; large 
mononuclear cells are present in the sinuses and lymphatics. An overgrowth of 
fibrous tissue has occurred in the tissue near the capsule. Many cells stain badly, 
but this may be due to decomposition. This is especially the case with the liver 
and kidneys. 
