46 aSSOPHAGOSTOMIASIS IN MAN.
Caecum.
External Surface. — The walls of the caecum are mottled all over with bluish-black irregularly shaped areas, especially along the anterior and posterior longitudinal bands. These areas are covered by the peritoneum, and on incising are found to contain encysted worms.
The appendix at its junction with the caecum is sur- rounded on two sides by a bluish tumour mass, which so distorts its lumen as to make it almost impossible to introduce a probe through the canal into the caecum.
Near the tip of the appendix, a bean-shaped nodule, 8 by 10 mm., is growing from the external muscular and subperitoneal layers of the wall. It does not involve the lumen. On microscopic examination two other small tumours are found near the large one, and situated in the submucosa.
Interior. — A noticable feature is the extreme rigidity of the walls of the caecum and first part of the ascending colon. On opening the bowel one finds a series of cord- like prominent opaque masses infiltrating the walls of the caecum. They measure 1-5 cm. in length, with broad bases 9-2-2 mm., from which they radiate. The extent of these masses is best seen by holding the gut up to the light. The masses are situated between the internal muscular and submucous layers, and are composed of several nodules closely adjoining one another. On each of the cysts is an immature adult oesophagostome.
The ileo-caecal valve is thickened and very rigid. Five small submucous cysts infiltrate the wall.
The Ascending Colon.
The walls of the ascending colon are seen to afford lodgment for a great number of tumours. These tumours
