412 



TR YPA NO SO MI DM 



characterized by circular oedematous areas about the size of a two-shilling 

 piece, generally under the skin of the sides and hind-quarters, but sometimes 

 also under that of the neck, shoulders, and thighs. This eruption is very 

 variable, and may appear in the morning and disappear at night, but generally 

 it lasts a week, and leaves the animal in a feeble condition. There is also 

 synovial engorgement of the joints and tendon-sheaths, and enlargement of 

 the lymphatic glands, particularly the inguinal. The temperature is often 

 raised to 39° C. (102-2° F.) in the evening, and falls to 38*5° C. (101-4° F.) in 

 the morning. 



Stage 3, or the Period oj AncBmia and Paralysis. — The animal now becomes 

 very anaemic, with pale mucosae, and emaciation is marked. There are often 

 superficial abscesses which do not heal, and some conjunctivitis and ulcerative 

 keratitis. Micturition is difficult, and the urine is thick. Sensibility is 

 diminished, and paralysis comes on, due to softening of the cord, and in from 

 two to eighteen months the animal dies. The disease is said to be always fatal. 



The above is the usual type of the disease, and may be called chronic 

 dourine, but in addition there is an acute type, in which the animal dies after 

 the first stage from acute paralysis, which comes on suddenly a few days 

 after the appearance of the eruption. 



The post-mortem lesions are in the spinal cord and the lymphatic glands. 

 In the cord there is gelatinous exudation around the lumbar area, and cervical 

 enlargement with intense chronic inflammation of the posterior spinal ganglia , 

 with degeneration of the perikarya and their associated neurones, causing 

 degeneration of the posterior roots and columns, as in tabes dorsalis. 



The grey matter of the cord also shows chromolytic changes, with capillary 

 haemorrhages due to chronic inflammation. Mott says that the infiltration 

 and thickening of the septa of the cord, the infiltration of the nerve roots and 

 the vessel walls with lymphocytes, is like a syphilitic meningitis. The mem- 

 branes at the base of the brain may also be affected . The lymphatic glands are 

 enlarged, congested, and softened. The disease appears to begin by inocula- 

 tion, and then to spread to the inguinal glands, and then to the pelvic lympha- 

 tics, and from them to the posterior lumbo-sacral roots, and thus the cord 

 becomes affected. Other lesions are gelatinous exudation under the skin, 

 serous effusions into the pleural and peritoneal cavities, wasting and pallor 

 of muscles, with fatty degeneration and an interstitial keratitis. 



Genus Duttonella Chalmers, 1918. 



Duttonella vivax Ziemann, 1905. 

 Synonym. — Trypanosoma vivax Ziemann, 1905. 



This trypanosome was found by Ziemann in 1905 in the blood of cattle, 

 sheep, and goats, suffering from ' souma ' in the Cameroons. Morphologically 

 it closely resembles T. cazalhoui, but it differs in the following : — 



1 . Rats are susceptible to T, vivax, but not to T. cazalboui. 



2. Cross immunity experiments indicate distinct differences. 



Bruce's T. vivax is T. cazalhoui, because rats are not susceptible to Bruce's 

 Uganda strain. It is possible that a strain allied to D. vivax has been found 

 by Macfie in human blood {vide p. 430). 



The flagellate is very rapid in its movements. A large kinetonucleus and 

 clear cytoplasm are present. It measures 16-3 1X2-3 microns, and has its 

 flagellum always free. It is pathogenic for equidae and ruminants. The 

 development is anterior in the tsetse-fly, being confined to the proboscis. 



Duttonella caprse Kleine, 19 10. 

 Synonym. — Trypanosoma caprcB Kleine, 1910. 



Found in sick goats near Tanganyika, it is capable of passing through its 

 cycle of development in G. morsitans in some nineteen days after infection. 

 Development only takes place in the proboscis. The final stage is in the 

 hypopharynx, where the trypanosomes revert to the blood form and become 

 infective. 



It is a heavily built trypanosome, with very rapid movements, measuring 



