393 



Drawings should be made of the head and 

 tail, and the mouth, anus, and vaginal orifice 

 carefully described. 



4. The description of the embryo. Where 

 found, blood or lymph. Presence of a sheath. 

 Length and breadth of embryo and sheath. The 

 exact description of spots and the distance of 

 these from the anterior extremity. The following 

 spots and markings may be seen : — 



(i) A transverse slit, about twenty-five per 

 cent, length. Sometimes not seen. 



(ii) A clear, sometimes lateral, sometimes 

 transverse spot, about thirty to forty per cent, 

 length. 



(iii) A long space in which the nuclei are 

 loosely arranged, often ending anteriorly and pos- 

 teriorly in clear space. About sixty-five per cent, 

 length. 



(iv) A small spot, about seventy-six per cent, 

 length. 



(v) Very small lateral spot or slit, ninety per 

 cent, length. 



Development of Filaria in the Mosquito 



Experiments made so far have been chiefly 

 with F. nocturna {F. hancrofti). 



Both Anopheline and Culicine mosquitoes may 

 act as the hosts of F. hancrofti. Certain species 

 of both genera, however, do not act as hosts. 

 The following have been shewn to act as hosts : — 



C. pipiens P. costalis 



C. ciliaris Mym. rossii 



C. fatigans Myz. sinensis 



