BY T. HARVEY JOHNSTON. 29 
Dr. Nicoll* of the Australian Institute of Tropical 
Medicine, Townsville, carried out a series of experiments 
which showed that the embryos do escape through the 
capsule of the nodule into the adjacent tissues and can 
eventually reach the surface of the skin, usually in small 
numbers but sometimes in greater quantity. He believes 
that a biting or blood-sucking insect is much more likely 
to be the transmitting agent than any aquatic organism. 
McEachran and Hillt have given attention to this 
problem in the Northern Territory and as a result of their 
investigations, recorded that practically every bovine there, 
no matter of what breed, except the buffalo, was parasitised 
by Onchocerca. They experimented with various arthro- 
pods, e.g., Tabanide, Muscide, midges, mosquitoes, lice, 
and a tick, and came to the conclusion that apparently 
“the intermediary host is not a biting fly or flying insect,” 
and moreover that lice may also be excluded. 
During last year (1915) Dr. G. Sweet published the 
results of her investigations in other parts of the world, 
and in her summary (p. 30, sgg.) has given a list of the species 
of Onchocerca and allied parasites occurring in various 
countries in the connective tissues and aortic walls of 
species of oxen, buffaloes, etc. She also recorded the pre- 
sence of a new species, O. indica, Sweet, from Indian cattle, 
closely allied to the Australian Onchocerca, whose original 
home appears to have been the Malay Peninsula where 
it occurs in Bos indicus. It is found in this host in Siam 
and Java also, and, in the latter country, occurs in the 
common ox, Bos taurus, as well. 
*W Nicoll “On the migration of the larve of Onchocerca gibsont 
through the capsule of the worm nodule.” Ann. Trop. Med. and Para- 
sitology, 8, 1914, pp. 609-621—Summarised in his paper ‘‘ Remarks on 
the Worm Parasites of Tropical Queensland ’’ Med. Jour. Austr., Sept., 
12, 1914. 
+ J. F. McKachran and G. F. Hill. Investigations into the cause 
of Worm-nodules (Onchocerca gibsoni) in Cattle at Darwin, Northern 
‘Territory, Australia. Bulletin of Dept. Trade afd Customs, Common- 
wealth of Australia, 1915. 
+G. Sweet. Investigations into the occurrence of Onchocerciasis 
in cattle and associated animals in countries other than Australia. Bull. 
Dept. Trade and Customs, Commonw. Austr., 1915. 
