188 T. H. JOHNSTON AND J. B. CLELAXD. 



tumours and thinks that they reach the lymphatics and 

 finally the general circulation, and that consequently the 

 transmitting agent might be a biting insect (l\ibauus, 

 Glossiua, Simidiitm). He believes that transmission of O. 

 reticulata occurs in the same way. As stated above, we 

 have not succeeded in finding embryos of O. gibsoni in the 

 blood of cattle. 



Parsons' mentioned that in the case of F. volvulus, the 

 parasite lives in a local dilatation of a lymphatic, and that 

 the embryos probably pass from these into the general 

 circulation, but that no observer had yet detected the 

 microfilariae in the blood. By analogy, he considered the 

 transmitting agent to be some blood-sucking insect. 



Addendum: — While this paper was in the press, one of us 

 received from Professor A. Railliet of Alfort, France, 

 amongst a number of reprints, a paper dealing with "Les 

 Onchocerques etc." by Railliet and Henry (C.R. Soc. Biol. 

 Paris, lxviii, 1910, p. 248 - 251). In this note the authors 

 cover some of the ground that we do in the above paper. 

 They re-establish Diesing's genus Onchocerca- with O. 

 reticulata, Dies, from the loot of the horse as type, making 

 a new species O. cervicalis for the parasite infesting the 

 cervical ligaments of the same animal. Filar la volvulus, 

 Leuckt. is also brought into this genus. A fragment of a 

 female nematode taken from a worm-nest from the subcu- 

 taneous tissues of the head of a dromedary in the Punjab, 

 by A. S. Leese, is describe:! as belonging to a new species 

 O. fasciata. The oidy information given concerning it is 

 that the breadth is from 403 to 475/s and that the cuticle 

 possesses feebly undulating ridges repeated at every three 

 or four striae. We have compared the Onchocerca (females) 

 taken from the West Australian dromedaries, with that 

 from local cattle, and notice that in the former the ridges 



