170 



<j;-ame is abuudant at certain seasons of the year, and goats and 

 dogs are kept in many of the villages. Tsetse-Hies are common 

 near some of these, and domestic stock, such as there is, appears 

 to thrive. Trypanosomes were occasionally fonnd m goats. 

 Tables are given showing the occurrence of trypanosomes m 

 various kinds of game. The percentage of big game infected 

 with trypanosomes in the Luangwa Valley is estimated at 50 

 and at Ngoa at 35. Six species of these parasites were isolated 

 from game at Nawalia. 



In Section III. the authors discuss trypanosomes found m wild 

 G. morsikuu. The flies were brought to the laboratory and fed 

 on clean monkeys which were the only animals available for the 

 purpose. Out of 3,202 flies used, at least 19 were capable of in- 

 festing monkeys at Nawalia and at Ngoa 5,250 flies gave the 

 following results: — 1:312 were found to be infected with 

 T. ignotum, 1:1312 with T. rhodesiense and 1:5250 with 

 T . 'pecorwni. 



In Section IV. trypanosomes are described and figured and in 

 Section V., in conjunction with L. Lloyd, the authors discuss the 

 development of T. rhodesiense in G. morsitans, summarising 

 their results as follows : — 



1. The salivary glands of all G. mursitans capable of trans- 

 mitting T. rhodesiense are infected, and conversely, without 

 invasion of the salivary glands there is no infectivity of the fly. 



2. Invasion of the salivary glands is secondary to that of the 

 intestine. 



3. The first portion of the developmental cycle of the trypano- 

 some takes place in the gut. In order for its completion and for 

 invasion of the salivary glands to occur, a relatively high mean 

 temperature (T5°-85° F.) is necessary. 



4. Invasion of the salivary glands was only found in flies 

 infected with the human trypanosome, T. rhodesiense. 



5. The predominant type of the trypanosome in the intestine 

 of infected G. morsiMns — a large broad form — is quite different 

 from that which predominates in the salivary glands, where the 

 parasite resembles somewhat the short form seen in the blood of 

 the vertebrate host. 



6. Both the intestinal forms and also those from the salivary 

 glands of infective G, morsitans are virulent when inoculated into 

 healthy animals. 



In Section VI. the entomologist, Mr. L. Lloyd, describes the 

 method of handling G. morsitans in the laboratory and says that 

 the flies were fed on native fowls at Nawalia and afterwards for a 

 short time on goats ; at Ngoa they were fed first on fowls and then 

 entirely on goats which died quickly under the repeated feedings, 

 doubtless owing to the trypanosomes with which the flies were 

 naturally infected. He then goes on to describe some breeding 

 places of G. morsitans near Ngoa, with plates, showing that the 

 pupae were found in association with trees of eiglit different 

 species and in holes in the earth. All these trees were either 

 abnormal or injured. No pupae were found at the bases of 

 normal trees or bushes and tliey were generally, though not 

 always, hidden under a slight covering of earth or dead leaves. 



