Symptoms. 809 



to normal or below, whereupon the animals become livelier 

 and the other sjanptoms diminish or may disappear entirely. 

 If the fever has lasted for a longer time the patients have in 

 the meantime become emaciated in spite of the fact that the 

 appetite has not been impaired much. After a certain time 

 the afebrile period is again followed by fever, and from then 

 on several fever days alternate with fever-free intervals, only 

 that the rises of temperature in the later course are lower 

 than in the first attack. 



Under such variations of temperature the animals become 

 emaciated, although their appetite continues very good, and 

 a pronounced anemia usually develops in which the hemoglobin 

 content may drop to 25 7o of the normal, Avhile the number 

 of red blood corpuscles may diminish to 214 millions per cubic 

 mm. with a simultaneous moderate increase of leucocytes 

 (Schilling; Nierenstein found in experimental nagana an in- 

 creased acidity of the blood, probably due to the production 

 of amido acid). Accordingly the mucous membranes appear 

 pale and in the later stages frequently icteric in color. 



The edematous swellings which develop on different parts 

 of the bodies vary in the first period in their intensity and 

 may sometimes disappear entirely; in the later course, how- 

 ever, they remain constant. Urticaria sometimes appears 

 especially at the beginning of the affection, but soon disappears 

 again. 



With the progressive emaciation and anemia the animals 

 become steadily weaker, their motions are incoordinated and 

 staggering, the animals knuckle frequently, and gradually a 

 condition resembling lumbar paralysis develops, so that the 

 patients, in which difficulty in respiration has appeared in the 

 meantime, remain continually lying down until they die, greatly 

 emaciated and completely exhausted. 



After artificial infection of dogs, Spielmeyer observed recent degeneration of 

 nerves in the posterior roots of the spinal cord, in the roots of the sensory tri- 

 geminus, and of the optic nerve. 



In some of the chronic cases an opalescence or an ulcerative 

 breaking down of the cornea results later or a hemorrhage 

 follows into the anterior chamber of the eye, which becomes 

 associated with an iritis, and finally leads to blindness. 



The urine periodically contains albumen in varying quan- 

 tities. The blood contains trypanosomes in great numbers dur- 

 ing the first febrile attack, while later they are found more 

 sparingly, usually only during the febrile attack. In the very 

 acute cases they usually occur constantly, and their number 

 may amount to 70,000 per cubic centimeter of blood. They 

 may also frequently be demonstrated in the serous fluid of the 

 swellings. 



The course usually extends to II/2 or 2 months, but may 

 sometimes last for 4 or 5 months. In some cases, which for 



