BY T. HARVEY JOHNSTON. 97 
The Hydatid. 
Echinococcus granulosus, B., more commonly known 
as Tenia echinococcus, Sieb., was stated by Lendenfeld* 
(1886) to infest it. This author referred to the common 
occurrence of the cystic or hydatid stage in human beings 
in the dry inland districts of Australia where dingoes were 
plentiful and the water supply scanty, both man and beast 
depending on water holes whose contents were frequently 
contaminated. He regarded the dingo as the agent 
responsible for infecting such water supply, and thus the 
chief transmitter as far as man was concerned. He 
examined many dingoes, and in 80 per cent. of those 
searched, found from one to five cestodes which he regarded 
as 7’. echinococcus in spite of the fact that they were much 
longer than the latter, often reaching to 10 or even 30 mm. 
in length. He mentioned that the hydatid tapewormf 
occurred commonly in the domestic dog in the mountainous 
region of Eastern Australia. Jendenfeld has certainly 
confused two or more species, as Echinococcus granulosus 
is a very small cestode, the longest that I have from the 
domestic dog (from New South Wales and South Australia), 
reaching only 2.5 mm., the average being about 2 mm. 
Dr. Angas Johnson did not find the species in the one 
dingo examined by him, nor was I successful when searching 
the Eidsvold material. 
The chief transmitting agent of the hydatid is 
undoubtedly the domestic dog, but I think that dingoes 
also harbour the cestode and contribute to its dissemination 
amongst Australian cattle, sheep, marsupials, etc. 
As regards the species which Lendenfeld actually 
found, I would sugge;t that it was either a new species, 
*J am indebted to Dr. 8. J. Johnston and Miss Marie Erhard, of Sydney 
University, for forwarding a copy of this paper to me from Sydney, as it 
was not available in Brisbane. 
{The prevalence of hydatids in man and the dog in Australia, especially 
in the south-eastern corner, had previously been emphasised by Dr. D, 
Thomas, P.R.S., Lond., 38. 1885, p. 444-57; Jbid., p. 457-8 (in 40 per 
cent, of the dogs examined by him, and in 50 per cent. of those examined 
from Melbourne); ‘‘ Hydatid Disease with special reference to its 
prevalence in Australia,” Adelaide, 1884; Trans. Roy. Soc., 8. Austr., 
-4, 1880-1; Jbid., 6, 1883; ete. 
G - 
