95 



% 



of the parthenogenetic type, i.e., heterogamy (see page 13 

 of " Catechism " Zoology, Part /.). Further, the partheno- 

 genesis here exhibited is strictly paedogenesis, i.e., develop- 

 ment of young by a sexual (parthenogenetic) process from 

 individuals not adult. 



Name three Trematodes which are Parasites of Man, and 

 state what you know about them. 



Fasciola (syn. Distomum) hepatica, the Liver-fluke of the 

 sheep, is a rare incidental parasite in the liver of Man. Tt 

 appears to be frequent in North Lebanon as a parasite in the 

 pharynx, causing the illness known as " Halzoun." 



Paragonimus ringeri, a pulmonary fluke, in Japan and 

 China, is found in the lungs and bronchi. 



Schistosoma (syn. Bilharzia) haematobium, the Blood- 

 fluke of Man, is common in Egypt and occurs frequently 

 in other parts of Africa. It is a parasite of the blood vessels, 

 particularly the portal vein and its tributaries, and is the 

 cause of endemic haematuria. 



The sexes are separate. The male Schistosoma is about 

 half an inch long and has a rounded appearance, the edges 

 of the body being rolled in ventrally to form the gynae- 

 cophoric canal in which the longer and thread-like female 

 is carried about. The egg has a peculiar terminal spine. 

 The natural intermediate host is a freshwater snail, Bullinus. 



CLASS CESTODA (TAPEWORMS). 



Write a general Description of a typical Tapeworm, e.g., 

 Taenia solium. 



The so-called head and the thin neck together form the 

 scolex, the small vegetative portion of the body. The 

 succeeding generative portion is a tape-like series of about 

 800 flat joints or proglottides, varying in length from two 

 to three metres. 



The scolex is globular : it has four hemispherical suckers 

 round the base, and a crown or rostellum with a circlet 

 of recurved hooks. 



