On N'igana, or Tsetse Fly Disease. [f)7 



cleated red corpuscles (normoblasts) often appear, especially in rats. 

 According to observations on rabbits the diminution of haemoglobin is 

 roughly proportional to that of the blood corpuscles. 



Leucocytosis is not a constant feature and when present is ap- 

 parently due to the febrile temperature. An excessive leucocytosis, 

 such as occurs in leukaemia, was never observed; 15,000 34,000 

 leucocytes being the highest numbers recorded per cubic millimetre. 



Blood drawn from an animal seriously ill, when clotted, generally 

 exhibits a marked buffy coat; the serum is often turbid and may 

 undergo secondary clotting. 



Instead of forming rouleaux, the red corpuscles tend to clump into 

 masses and to lose their outlines, especially when the anaemia is pro- 

 nounced (rabbit, ass, and horse). 



The serum of such blood, when mixed with normal blood of the same 

 species of animal, causes the red corpuscles to clump together also. 



The urine of infected dogs spectroscopically examined often shows 

 an intense wobilm band. 



6. Wounds do not heal well, and tend to break down and become 

 septic, even though the operation has been performed with strict 

 aseptic and antiseptic precautions. The hsematozoa may be abundant 

 in the discharge from the wounds. Many animals, especially dogs, 

 are apt to become infected with pyococci and other bacteria in the 

 later stages of the disease, even when the inoculated material has been 

 proved to be free from bacteria. We conclude that a spontaneous 

 terminal bacterial infection may occur when the marasmus has reached 

 a certain degree. This may accelerate death and is probably fairly 

 often the case in the naturally acquired disease. But we have often 

 proved by cultures that bacteria are absent in uncomplicated cases of 

 experimental inoculation. 



7. A voracious appetite has not been observed in the infected labo- 

 ratory animals ; some animals refuse their food and the stomach is not 

 seldom empty after death. 



8. Rats and guinea-pigs often exhibit convulsive or eclamptic 

 seizures shortly before death, but otherwise guinea-pigs, rats, and mice 

 show no symptoms of disease, except dulness in the later stages. 



9. Transmission from one animal to another, without direct inocula- 

 tion, has never been observed. Nor have we come across instances of- 

 infection by coitus or through suckling, although we have dealt with 

 laroje numbers of animals. 



V. Morbid Anatomy. 



In rats and mice exactly the same conditions may be observed. The 

 most striking changes are : 



(1) Enlargement of the lymphatic glands, the glands corresponding 



