Parasites. 287 



migration, sometimes passing from the shoulder to the 

 forearm or hand, or from the thigh downwards to the 

 foot. Its presence may be recognised by a peculiar 

 cord-like feeling beneath the skin. It may give rise to 

 abscesses and severe inflammatory disturbances, rarely 

 fatal results have been recorded. They are by no means 

 always easy of extra6ling whole, the worm usually 

 breaking before extra6lion is completed. The usual 

 method is to wind off the worm on a piece of stick, or 

 the application of a steady stream of water to the affefted 

 part. When the parasite is mature and ready to leave 

 its host, a small bleb forms, the fluid of which contains 

 numerous young Filaria which have been eje6led from 

 their parent. This ejetlion of young guinea-worms con- 

 tinues for a variable period, the time for the extraftion 

 of the parent worm corresponding with the cessation of 

 the emissions of the young. 



For some time it was held that the guinea-worm found 

 ingress to the human body through the dufts of the 

 skin, as in those who go about bare-footed in swampy 

 places, or bathe in water abounding with microscopic 

 tank-worms (Carter). But Fedschenko has dis- 

 covered that the " escaped embryos of the worm perforate 

 the skin of minute crustaceans ; here, after a period of 

 only twelve hours, the embryos undergo a fresh change 

 of skin. At the end of one month and six days they 

 acquire their highest larval stage of growth, and then 

 with their intermediate hosts, they are transferred to the 

 human stomach. The males eventually perish, and the 

 females migrate through the tissues of the body to the 

 skin. Hence we see that in all probability the guinea- 

 worm is conveyed to the human frame by means of 



