DRAG UNO ULUS MEDINENSIS. 387 



not be unreasonable to cut down upon the wanderer and arrest 

 his progress, particularly if there seemed to be any marked ex- 

 ternal vesicles or elevations of the integument. Speaking prophy- 

 lactically, all persons travelling in Gruinea-worm districts, should 

 be careful to protect their feet and legs during the rainy season, 

 and especially also should they be scrupulously careful, after wash- 

 ing or bathing, to wipe themselves thoroughly dry — if possible, 

 with warm or hot towels. In this way only can they be tolerably 

 sure of preventing the incompletely-developed, but probably 

 sexually-mature female Dracunculi from gaining access to their 

 bodies. 



Summary. — After a careful survey of all the more prominent 

 facts and phenomena connected with the life-history, development, 

 and propagation of the Gruinea-worm, I offer the following con- 

 clusions : — 



1. The Guinea- worm, as commonly known, is the adult female 

 condition of a nematode parasite, forming a distinct generic type 

 for which the title of Dracunculus ought still to be retained. 



2. The female Dracunculus is parasitic only during the final 

 stages of its life-period, after it has taken up its residence in the 

 subcutaneous and intermuscular cellular tissues of man, dogs, and 

 horses. 



3. The adult female reproduces viviparously; and, in consequence 

 of an enormous development of the internal reproductive organs, 

 contains myriads of embryos in all stages of development. 



4. The embryos, when set free, are capable of sustaining an 

 independent existence ; their vitahty is so tenacious that, after a 

 more or less complete desiccation, they will revive on the applica- 

 tion of moisture, 



5. The proper habitat of the free active embiyos may be either 

 the fresh water of natural stagnant pools, the damp mould and 

 mud of low-lying marshy districts, or especially, the soft, ochreous, 

 argillaceous clayey soil forming the bottom of wells, tanks, and 

 other artificial reservoirs. 



