174 



The hal)ita1 par excellence of tlie larvae of A. luteola is sand 

 and dust on the iloors of native houses, and they can always be 

 found by digging' in the soil underneath a sleeping mat, provided 

 that the natives sleep either directly on the soil or upon mats very 

 slightly raised from its surface. The moment that the native 

 raises his mat a very few centimetres above the soil the maggots 

 disappear. In those cases in which the floor is strewn with loose 

 earth the maggot abounds. The author cites districts in which 

 this practice prevails, and says that in one such hut in which a 

 dozen children were sleeping he captured 100 larvae in half an 

 hour. 



The fact that the wart-hog does not make its own burrows but 

 occupies those of the ant-bear, probably accounts for the fact that 

 Choetomyia choerophaga and C. houeti often occur together in the 

 same burrow. Although no larvae of C. praegrandis were 

 obtained, adult flies were found in the burrows of Orycteropus 

 senegalensis ; but in no case was A. luteola found in such situations. 



The author describes in detail the manner in which the larva of 

 A. luteola feeds and the process by which it fills itself withblood 

 when once it has succeeded in producing a bleeding abrasion of 

 the skin; it generally bites a man on his side and under the arm. 

 The larvae can be raised experimentally upon the bodies of young 

 pigs. 



As a result of various experiments, the author concludes that 

 the sensibility of the larvae to heat is dependent upon the need 

 for food. For example, carefully conducted experiments with 

 larvae placed in sand heated from above by a metal disc, showed 

 that when the temperature rose to 31° C. starving larvae would 

 move towards the source of heat, but beyond 38° C. the larvae 

 tended to retire. But larvae which had been recently gorged did 

 not move towards the source of heat, and when the temperature 

 of the disc passed a certain degree they moved away from it. Ex- 

 periments with larvae kept at a temperature of 35° C. showed that, 

 in spite of feeding, death ensued about the 10th day. Growth 

 was interfered with, and the larvae exhibited an abnormal activity. 



The length of the larval life of these flies is of necessity some- 

 what difficult to determine, but according to the author's experi- 

 ments, the results of which are set out at length, the growth and 

 life of the larva is profoundly affected by food, and he found that 

 under the best conditions of food and temperature .4. hiteola 

 required 15 days before pupation, and that in this period two 

 moults took place. Experiments were made on the effect of starva- 

 tion and other conditions at the period of pupation, which tend 

 to sliow that the date of pupation can be retarded by want of food, 

 the larvae of A. luteola living 71 days and 76 days under these 

 conditions before pupation took place. The author says with 

 regard to the bite of these larvae, that the smaller they are the 

 greater the pain, thougli this is in no case of any consequence, 

 producing less irritation than the bite of a mosquito. In his own 

 case, he found tliat the bites of about 20 larvae at the same time 

 were not followed by either inflammation or itching. The bite of 



