26 Sir D. Bruce and others. G. brevipalpis as a 



Table V. 



Expt. 



Time, days. 



Proboscis. 



Alimentary tract. 



Salivary elands. 



2201 



30 





+ 





2201 



37 





+ 





2213 



33 





+ 



+ + + 



2213 



46 



+ 



+ + 





2232 



37 





+ 





2232 



37 





+ 





2232 



44 





+ 





2232 



44 





+ 





In Experiment 2201 there were two infected flies found. One of these 

 appeared to be infected with T. grayi, the other with a trypanosome of a 

 pathogenic type. 



In Experiment 2213 there were also two infected flies. In one the 

 development was restricted to the proboscis and the alimentary tract ; in the 

 other the salivary glands as well as the intestine were found to be swarming 

 with trypanosomes. This fly, which was dissected 33 days after it had fed 

 on an infected monkey, had the whole lumen of the glands filled with active 

 motile trypanosomes, which came pouring out of the broken end- of the 

 glands. It was thought at the time that these must be infective forms of 

 the trypanosome causing disease in man in Nyasaland, but a part of the 

 salivary glands and contents of gut injected into a white rat failed to infect 

 it. In spite of this negative experiment, however, it is probable that 

 this represents a true development of the Nyasaland trypanosome in 

 G. brevipalpis, the development not having reached the infective stage. A 

 fuller description of the morphology of these salivary forms will be given 

 under the next heading. It may be noted here that salivary glands infected 

 by T. brucei vel rhodesiense or by T. brucei, Zululand, 1913, seem to be more 

 crowded with trypanosomes than in the corresponding infection of 

 G. palpalis by T. gambiense. The salivary glands in the former case appear 

 to be swollen and bursting with the flagellates. 



In Experiment 2232 there were four infected flies found, but in none was 

 there any invasion of the salivary glands. 



(d) Morphology of the Trypanosomes found in the Salivary Glands of a Wild 

 G. brevipalpis which had fed on a Monkey infected vjith the Trypanosome 

 causing Disease in Man in Nyasaland. 

 This fly, as described above, was found in Experiment 2213, and failed to- 



infect the clean Dog 2237 which it had been fed upon. Part of the salivary- 



