3°4 



MANUAL OF ELEMENTARY ZOOLOGY 



and larvse escape into the host's tissues, sepsis, fever, and even death 



may result. . . 



6. Larva and adult parasitic, without free stage, in animals 0} 



unlike kinds.— The supposed cause of elephantiasis, Filaria bancrofti, 



Fig. 213. — The Guinea 

 Worm (Dracunculus 



medinensis). 



A , Adult female, reduced ; 

 J3, larva, much magnified. 



Fig. 214. — Cyclops. 



ad. 1 , First abdominal segment ; a/. 1 , antennule ; 

 at.^, antenna; c./. % caudal fork; cph,, 

 cephalothorax (fused head and first two 

 thoracic segments) ; c .3-., _ egg sac ; eye 

 (single and median); £"., alimentary canal ; 

 gcn.op.y genital opening; t., telson ; M. 3 , 

 th.% third and sixth thoracic segments. 



In comparing this crustacean with the 

 crayfish, note the absence of proventi iculus, 

 paired eyes, uropods, and carapace, the 

 presence of median eye and caudal fork, 

 and the difference in the number of seg- 

 ments. 



lives and pairs (male 8-9 cm., female 15 cm.) in the human lym- 

 phatics. The female is viviparous, setting free embryos into the lymph, 

 whence they reach the blood and are sucked up by mosquitoes or gnats, 

 in which they bore through the wall and develop in the muscles. 

 Later they enter the salivary glands and are injected into man during 



