34 ° 
Morphology. —17-28 by 1*5-3/^. The blepharo- 
plast is oval. There is not uncommonly a vacuole 
in close association with it. The trypanosome, 
at least in animals, occurs in two main forms, a long 
and a short. With regard to the alleged sexual forms 
occurring in the fly vide p. 341. 
The Spleen .—Is considerably enlarged and con- 
Brain .—The pia-arachnoid shews patchy thicken¬ 
ing and opacity, especially at the base. Microscopically 
the brain shews an absolutely characteristic change, viz., 
chronic inflammation of the perivascular lymphatics. 
Around the vessel there is always present a neuroglia cell 
proliferation, and the branches of these cells form a 
reticulum. In this reticulum occur a large number 
of lymphocytes and plasma cells of Marschalko (p. 8). 
Besides this characteristic cell there are found also 
makrophages, which are possibly altered perivascular 
lymphatic endothelial cells ; so-called morular or 
granule cells, i.e ., cells containing a number of spherules 
that stain with eosin ; and degenerated trypanosomes 
and chromatin particles, probably nuclear remains of 
the former. 
Lymphatic Glands .—Are soft and moveable, and 
the deeper ones may be as big as a walnut. They shew 
increased vascularity (haemolymph glands) and chronic 
inflammatory changes resembling those in the brain, 
viz. :— 
(1) Lymphocytes in all stages up to plasma cells 
occur. 
(2) Proliferation of the connective tissue cells of 
the reticulum of a lymph sinus, and marked prolifera¬ 
tion of the nuclei of the endothelial cells. 
(3) When the inflammation subsides they become 
fibrous. 
