284 THE ANIMAL PARASITES OF MAN 



Filaria medinensis in its adult stage lives beneath the surface 

 of the body ; it is seen most frequently on the lower extremities, 

 more especially in the region of the ankle ; but it also occurs in 

 other parts of the body on the trunk, scrotum, perinseum, on the 

 upper extremities, and in the eyelids and tongue. As a rule, 

 there is only one ulcer and one worm, rarely several. It attacks 

 man without distinction of race, age or sex. It is observed most 

 frequently during the months of June to August. 



The following is known of the development of this filaria : The larvae, 

 which in form resemble those of Cucullanus- belonging to the order of 

 the Nematoda, can only reach the open after the bursting of the mother's 

 body. For a few days they live in water or moist soil, and can with- 

 stand desiccation for a few hours. In consequence of their similarity 

 to those of Cucullanus elegans (parasite of Perca fluviatilis\ which live in 

 Cyclops, Fedschenko, by the advice of Leuckart, introduced the larvae of 

 the filaria into water containing cyclops, the larvae of insects, &c., and 

 was able to confirm their invasion of the cyclops (not per os ) but through 

 the integuments of the body). On about the twelfth day they cast their 

 skin and assumed- another form. They could be observed within the 

 cyclops until the fourth week, yet no changes occurred though the larvae 

 grew to a length of i mm. The experiment to infect young cats and 

 dogs with filariae by giving them infected cyclops in milk or water failed. 

 There is, however, always the possibility that the infection of man is 

 accomplished in this manner. A series of observations appear to demon- 

 strate that the period of incubation averages from eight to ten months. 



P. Manson and R. Blanchard have recently repeated the infec- 

 tion experiments with fresh-water cyclops, and have convinced them- 

 selves of the correctness of Fedschenko's observations. Daphnidae 

 were not used, only Copepodse (Cyclops strenuus, C. bicuspidatus, 

 and C. viridis). As the species mentioned are indigenous forms, 

 Blanchard thinks the probability is not excluded that the Medina 

 worm if imported and such importation does occur may also 

 settle in Europe. 



LITERATURE. 



BASTIAN, A. On the Structure and Nature of the Dracunculus. (Transact. Linn. 



Soc., 1863, xxiv., p. 101.) 



LEUCKART, R. Die menschlichen Parasiten, &c. (1876, i., Edit, ii., p. 644.) 

 FEDSCHENKO. Bau und Entwickelung der Filaria. (Ber. d. K. Ges. der Frde. d. 



Natur. Anthrop. u. Ethnogr., 1879, viii. [i], p. 71, i plate, Russ.) 

 MOSLER, F. Ueber die medic. Bedeutung des Medinawurmes. Wien, Lpzg., 1885. 

 CHARLES, R. TL History of the Male Fil. med. (Scientif. Mem. Med. Omc. Army 



of India, vii., 1892, Calcutta.) 

 RAILLIET, A. De 1'occurence de la Filaire de Medine chez les animaux. (Bull. soc. 



zool. de France, 1889, xiv., p. 73.) 



BLANCHARD, R. Mai. par., par. anim., Paris, 1895, p. 768. 

 MANSON, P. On the Guinea-worm. (Brit. Med. journ., London, 1895, ii., p. 1350; 



The Lancet, 1895, xxxvii., ii., p. 309.) 



