May, '08] ENTOMOLOGICAL NEWS. 225 



in 1872 by the Portuguese from South America. Since then 

 it has traversed the continent and is steadily pursuing its way 

 around the world, having already been carried by coolies from 

 East Africa to the Far East. S. penctrans in Angola lives in 

 the dust, etc., on the floors of native Kraals, camps, etc. It 

 bites all warm-blooded animals, including man, in the same 

 manner as do ordinary fleas ; but if a 2 be impregnated, she 

 takes advantage of her first chance to burrow into the tissues 

 of some warm-blooded animal (often man) thereby occa- 

 sionally causing tetanus, sepsis, gangrene, mutilation and (rare- 

 ly) death of her host. Once ensconced, she matures her eggs, 

 her abdomen, which admits of enormous distension, swelling 

 during the process to the size of a sweet pea. There have ap- 

 peared various accounts of the succeeding steps in the meta- 

 morphosis, many of them inaccurate. In books on zoology, 

 pathology and medicine we read, for instance, such statements 

 as these : The eggs are "not deposited while the parasite is 

 in the skin, for the ova do not leave the body until the parent 

 reaches the soil." "The female bores into the skin, and the 

 escaping larvae give rise to ulcers." "The female lays her 

 eggs in the skin and causes thereby intense inflammation." 

 "After the eggs are laid (according to some before this pro- 

 cess) the super jacent skin ulcerates and the chigger is ex- 

 pelled," etc., etc. During the examination of large numbers 

 of natives in Angola, I have made the following observations, 

 already published in another periodical/ 1 " concerning this dis- 

 puted stage in the life history : 



1. The eggs are always laid while the chigger is yet imbed- 

 ded in the flesh of her host.t 



2. They never hatch into larvae in the body of the parent. 



3. They are not laid at one time in masses,f but discretely 

 and sometimes at considerable intervals. 



*American Jour. Med. Sciences, May, 1906. 



fWhen artificially removed from the tissues of her host she behaves 

 abnormally and extrudes all her eggs at once, but this does not form a 

 real exception to the above statements, and only a few of the most 

 mature eggs thus expelled will hatch out. 



