220 MYIASIS 



mature it drops out, burrows in the ground, and becomes a pupa." 

 Austen (1908) suggests the fly may lay its eggs in flannel or 

 woollen clothing hung out to dry. The fly hatches in 

 sixteen or seventeen days, Blenkinsop (1908) states that 

 " in the majority of cases a single larva is found in an 

 individual at a time," but that in some cases as many as 

 twenty-four are found. Marshall (1902), working in Rhodesia, 

 makes the following remarks : " It has been a great scourge this 

 year in Salisbury, especially among young babies, the maggots 

 forming a painful boil-like swelling under the skin. One baby 

 had no less than sixty maggots extracted from it, and there 

 have been several cases in which there have been a dozen or 

 more." Among Europeans the scrotum and upper part of the 

 thigh and buttock are favourite sites, and " it is the generally 

 received opinion that the parasites are often acquired at the 

 latrine." Amongst natives " no special region seems to be 

 selected." " In monkeys the tail is the favourite site of 'tumbu' " 

 (Smith). 



Smith (1908) gives the following description of the disease : 

 " In the human being the appearance of the lesion produced by 

 the larva is that of a raised reddish patch ; on a clean, washed 

 skin it looks something like an urticarial wheal. At some part 

 of this .swelling will be seen a tiny opening, or a moist spot, 

 perhaps a blackish mark, according to how much, if any, of the 

 larva is presenting at the opening and to the stage of growth. 

 In some cases where the skin has not been washed, pus may have 

 exuded or scabbed round the orifice, so that the appearance is 

 that of a broken boil. There is intense itching in and around 

 the spot. Strong pressure towards the opening forces the larva 

 out easily enough, so that in adults familiar with the fly the larva 

 does not get a chance to grow very big, unless it happens to be in 

 a part where the sufferer cannot see what is wrong. In neglected 

 children and helpless people the larva is able to grow to its full 

 size. In such cases there is usually suppuration in the cavity, 

 and it is common on ejecting the intruder to see a bleb of pus 

 follow it out. I have not iieard of any serious results from the 

 attacks of this larva, but as affording an avenue of entry to 

 germs, it seems likely that bad effects may occasionally follow a 



