300 THE ANIMAL PARASITES OF MAN 



9. Filaria loa, Guyot, 1778. 



Syn. : Filaria oculi, Gerv. et. v. Ben., 1859 > Dracunculus oculi, Diesing, 1860 ; 

 Dracunculus loa, Cobbold, 1864 j Filaria subconjunctivalis, Guyon, 1864. 



The male measures 22 30 mm. in length, and 0*3 0*4 mm. 

 in breadth ; the cuticle is not striated, but, with the exception 

 of the anterior and posterior extremities (1-5 mm.) is beset with 

 numerous irregularly distributed protuberances. The anterior 

 extremity is somewhat narrowed, and in front is conical and 

 transversely obtuse. On each side of the posterior border of the 

 conical part is a small papilla corresponding to the dorsal and 

 ventral median ridges. The posterior extremity is attenuated and 



somewhat curved ventrally ; the anus 

 is 0-082 mm. distant from the rounded 

 posterior border. In front of the anus 

 on each side are three globular and 

 pedunculated papillae of different sizes, 

 set close one behind the other ; behind 

 the anus on either side are two smaller 

 papillae of a different shape ; the ante- 

 rior one resembles the pre-anal papillae 

 in form, but is smaller ; the posterior 

 FIG. 199. Filaria loa. The one j s conical, and rests on the cuticle, 



anterior end of the male, mag- , 



nified. (After R. Biajichard.) with a broad base. The spicules differ 



but little in their length. 



The female measures 32 41 mm. in length, by 0*5 mm. in 

 breadth. It is also beset with irregularly distributed chitinous 

 bosses, which in places stand close to each other, and extend to 

 the anterior extremity ; posteriorly they become less frequent, 

 but are not entirely absent. The anterior extremity is conical, 

 the posterior one straight, attenuated, rounded off. The vulva 

 apparently lies at the border of the first and second quarter 

 of the body ; the vagina, 3 mm. in length, forks off into two long 

 (10 cm.) tubes, extending almost throughout the entire length of 

 the body, the narrow end of which are the ovaria ; they contain 

 eggs in the most various stages of development, as well as hatched- 

 out larvae, 0-253 0*262 mm. in length, and 0*0047 0-005 mm - 

 in breadth. Their anterior extremity is rounded, the posterior 

 extremity is slender and awl-shaped ; the cuticle is smooth. In 

 addition to the rudiment of the intestine the rudiment of the 

 generative glands also can be recognised 0*08 mm. behind the 

 anterior extremity. 



