NOTES ON SOME TROPICAL DISEASES 29 



2. That this species is probably that discovered by Forde and 

 described by Dutton, from the West Coast of Africa, and called by 

 him Trypanosoma Gambiense. 



3. That the so-called cases of trypanosoma fever described from 

 the West Coast may be, and probably are, cases of sleeping sickness 

 in the earliest stages. 



4. That monkeys are susceptible to sleeping sickness and show 

 the same symptoms and run the same course, whether the trypano- 

 somes injected are derived from cases of so-called trypanosoma fever, 

 or from the cerebro-spinal fluid of cases of sleeping sickness. 



5. That dogs and rats are partially susceptible, but that guinea- 

 pigs, donkeys, oxen, goats, and sheep, up to the present, have shown 

 themselves absolutely refractory. 



6. That the trypanosomes are transmitted from the sick to the 

 healthy by a species of tsetse fly (Glossina palpalis), and by it alone. 



7. That the distribution of sleeping sickness and G. palpalis 

 correspond. 



8. That sleeping sickness is, in short, a human tsetse-fly disease. 

 The actual discovery of trypanosomes was made by Aldo Castellani 



in cerebro-spinal fluid drawn off by lumbar puncture and centri- 

 fuged. 



It was the insight gained by the previous investigation of 

 tsetse-fly disease that enabled Bruce to realize the importance of 

 Castellani's discovery. He arranged for further observations to be 

 made, and these resulted in the trypanosome being recognised as the 

 cause of the disease. 



The genus Glossina (Wiedemann) appears to be limited to Africa. 

 The original tsetse fly (G. morsitans) is a good example of the 

 genus (see Part I. of this work). 



It may be asked what is found when the tissues of those who have 

 died of sleeping sickness are examined by the usual pathological 

 methods. 



We have a report of such a case by G. C. Low and F. W. Mott, 1 

 in which a diagnosis had been made from the symptoms before death, 

 1 G. C. Low and F. W. Mott, Brit. Med.Journ., April 30, 1904. 



