238 JAS.. .1. SIMPSON — ENTosroi-OGrcAi 



VI.— TSETSE-FLIES. 



Some of the Points on which Obseryations are wanted.. 



1. Locality. — Name of colony and nearest station, river, lake, &c. It is not 



always possible in England to identify native villages. 



2. Hhere caught. — On road, at ford, in village, close to villag^e, far from 



human habitation, orr railway, &c. 



3. Altitude, if known. 



4. Time of day. — If canght at night, ? moonlight. 



5-. Nature- of country. — River bank, grassy plain, dense forest, thorny scrubs 

 &c. 



6. Presence or absence of loater. 



7. Dry or loet seasoji. — State whether the grass or scrub ,ifi burned in the dry 



season. 



8. Presence of more than one species. — This is easily overlooked, as some 



of the species are very similar to one another, 



9. Numbers of fly. — Half-a-dozen, numerous, very numerous, swarms, &c. 



10. Ratio of the sexes.- — Males usually outnumber females. 



11. Do the flies bite through clothes ? 



12. Have you observed any bird or insect preying on the flies ? 



13. Do the flies go to the water to drink ? 



14. Are cattle, sheep, goats, or horses kept in the fly region ? 



15. Presence or absence of sleeping sickness. 



Observations carried on month after month at one spot are of more value than 

 spasmodic research in diverse districts. 



VII.— INSTRUCTIONS FOR COLLECTING LICE. 

 l.—Sucldng Lice (Anoplura). 



The true or sucking lice are placed by most systematists near the Rutnchota 

 (Hemipteea) and the Tbysanoptera. Their mouth organs partly consist of 

 very thin, long, piercing-bristles. These are, however, very difficult to see on 

 account of their extreme thinness and lack of all colour. By means of these 

 organs the Anopltra can be distingnished fi-om the so-called biting lice, 

 Mallophaga,. which live on the hair or feathers of their hosts and whose- 

 mouth parts are adapted to biting as opposed to sucking. 



The AjfOPLURA can be found on aU mammals of all sizes. In most cases they 

 can be combed out from the hair of their hosts with a common tooth-comb. In 

 the case of mammals with very &light pelage it is better to search the skin for 

 these parasites, which can be killed by dropping a few drops of chloroform on 

 them, and can then be removed with a small brush or a pair of forceps. As a 

 rule, only a few individuals of any one species of mammal are infested with 

 lice, bvit in these cases the insects generally occur in large numbers and 

 especially so if the animal is young or weak. It is very advisable, to 

 examine a large number of individuals of any one host, especially of those from 

 which no lice are as yet recorded. Lice are especially desired from all carnivora^ 

 such as cats, carnivorous whales, &c. Aquatic animals such as seals, are ofteis 



