66o SCIENCE PROGRESS 



describes a slightly motile bacillus, producing a pellicle on 

 bouillon, growing freely on potatoes, found constantly in the 

 blood in sleeping sickness, and never agglutinated by the 

 blood in these cases. Castellani has found a streptococcus 

 in non-complicated cases. His results were, however, in a 

 number of cases negative. 



Trypanosoma. — In November 1902 Castellani began to use 

 a special technique, and since then he has often observed, in 

 cases of sleeping sickness, a trypanosoma in the cerebro-spinal 

 fluid and the blood, and in some cases special bodies which 

 he looks upon as developmental forms of trypanosoma. In the 

 cerebro-spinal fluid also, very minute bodies have been found, 

 identical with the amoeboid forms described by Plimmer and 

 Bradford in Trypanosoma Brucei. 



Predisposing Causes. — Sex and age do not exercise any 

 influence on the incidence of the disease. Clarke speaks of 

 circulatory disorders, mental depression, and want of food as 

 predisposing causes. Any other causes of loss of resistance, 

 such as parasites like Filaria perstans, Ankylostoma deodenale, 

 etc., may act as predisposing causes. 



Symptoms and Clinical Features. — The disease begins insidi- 

 ously. First there is a slight mental change, next a disinclina- 

 tion for exertion, a tendency to sit about ; then there are 

 headaches and various transient pains, especially pains about 

 the upper part of the chest. The facial expression becomes 

 dull and apathetic. The disease may then run either an acute 

 or a chronic course to its fatal termination. On examination, 

 a patient with this disease is seen to present a dull, stupid 

 appearance, with slowness of thought and ideas. The speech is 

 slow, thick and indistinct, and the gait is shuffling. Headaches, 

 dizziness and vague pains are complained of. The tongue 

 sometimes presents a fine tremor, and in some cases there is 

 also a fine tremor of the hands. The skin may be either soft 

 and smooth or roughened and harsh. The glandular enlarge- 

 ments common among natives may become more noticeable. 

 The temperature is raised. The evening temperature runs up 

 from 101 to io2 c F., with a fall to subnormal in the morning. 

 There is often a daily range of 4 or more. The pulse is of low 

 tension, and of a frequency of from 90 to 130 a minute. The 

 temperature and pulse are very important as early diagnostic 

 signs. The patient is very drowsy and lethargic. When taken 



