166 Annals Entomological Society of America  |Vol. XIV, 
gave to them the name Filaria sanguinis hominis. In 1876 
Manson discovered the adults and in the following year he and 
Bancroft simultaneously suggested that they underwent a 
part of their life cycle in mosquitoes. This fact was very soon 
demonstrated by Manson, though many of the details have 
since been worked out. 
The larve occur in myriads in the blood of the affected 
individual but are found in the peripheral blood only at night. 
They are taken up by feeding mosquitoes and within the body 
muscles of the insect must undergo a development before they 
are capable of further development in man. In about three 
weeks they leave the muscles of the mosquito and settle down 
in its mouthparts, there to await the visit of their host to man. 
When the mosquito now feeds the larvae are not injected, but 
escape from the proboscis of the mosquito and actively bore 
into the skin of their new host, as does the hookworm. In 
this respect the procedure differs from that of malaria, in 
which the spores are directly injected by the mosquito. 
A related filarial worm Filaria ammitis lives as adult in the 
heart of the dog. In this as in the preceding species the larve 
are discharged into the blood and are taken up by mosquitoes. 
From the stomach of the insect they pass to the excretory or 
Malpighian tubules, and undergo their metamorphosis there 
instead of in the muscles. In about two weeks they are ready 
to enter the dog in the same manner as the preceding. 
The guinea worm, Dracunculus medinensis, is a filiform 
parasite of man, upwards of three feet in length, which lives 
under the epidermis, usually in the leg or foot. Over the 
vulva of the worm a small hole opens through the epidermis to 
the surface and through this the microscopic larve escape. 
The presence of the worm and its products often leads to 
very severe inflammation, to abscess and sloughing, and even 
death from secondary infections. The usual method of extrac- 
tion practiced by natives where the parasite is endemic is to 
wrap the protruding worm around a stick which is every day 
given a turn or two until the entire worm is drawn out. The 
parasite has been known since very remote periods. An illus- 
tration in Pigafatta’s account of his voyages to the Congo 
show that this method of extraction was practiced there in 1598. 
Agitharchides, 150 years B. C.,. gives an account of the disease 
