APHANIPTERA. 25 



wing (haltere) of the Diptera. This is a point worth noticing, that 

 in these Diptera the posterior rudiment is more developed than the 

 anterior, contrary to the usual arrangement of the wings in flies. 



Legs, long and strong ; the posterior pair formed for leaping. 

 Coxa; large. At the four hind legs the coxje articulate to the 

 epimer.'e by means of a supplemental joint, which is absent in the 

 fore leg. The trochanter is small. Strong femora and setose tibiae 

 ending in five-jointed tarsuses. The terminating tarsal joint bears a 

 pair of ungues, or claws. 



Sarcopsylla penetraiis ( = Pidex pe?ietrans). 



This species forms another genus in the Pulicidae. It is an 

 insect that has attracted a large amount of attention owing to its 

 unpleasant habits. 



The male is a small and insignificant insect, which does not seem 

 to be parasitic— at least, as far as we can make out from various 

 accounts. They are usually found in damp and swampy places, 

 and breed in great numbers, the ground swarming with them. The 

 female is the insect that has attracted so much notice. They are 

 known as "jiggers," or the "jighoe," and inhabit South America, 

 the West Indies, and the West Coast of Africa, etc. The females 

 attach themselves to the feet of travellers and to animals. They 

 chiefly fasten on to the spaces between the toes and under the nails. 

 As soon as they are attached to the skin they burrow into the flesh, 

 and there excavate a nest and attain a great size, often as large as a 

 pea. It is the abdomen only of the female that enlarges. This 

 enlargement is due to the development of the ova in the body. 

 Unless the "jigger" is extracted before this bursts a very nasty 

 wound is produced, leading to ulcerations, and maybe, the destruc- 

 tion of the bone, and amputation is rendered necessary. Wood, in 

 his " Insects Abroad," scouts this idea ; but I am assured that if left 

 to themselves they may produce the most serious wounds and disease. 

 They are, however, easily extracted if paid attention to at once. It 

 seems that the ulceration is set up by the larvae that are hatched, 

 and escape from the female. 



The larvse live for a certain time in the host, and then are said to 

 pass out and pupiate in the ground. 



The female is thus seen to be impregnated before she attacks 

 the host, otherwise no effect is produced. When their bodies are 

 fully swollen they very much remind one of the Brazilian honey-ants, 

 which have their abdomen enormously distended by honey. 



As such swarms of these "jiggers" are seen in certain localities. 



