490 QUEENSLAND AGRICULTURAL JOURNAL. [1 Junk, 1898. 
Science. 
HYDATIDS. 
By F. C. WILLS. 
, Tux term “hydatid” is one often used in the Australian colonies, but very little 
is known of the actual ravishes and prevalence of this disease by the public, 
and those who are especially in the dark are the very persons most affected by 
this parasitic immigrant. 
The object of this short paper is to place before such a few facts which 
have come under the writer’s notice by actual observation and through infor- 
mation gathered through having been engaged to assist in the investigation of 
hydatids in sheep. It is, in short, a scientific subject treated in a popular 
manner, so that the readers may get some idea of the enormous risk incurred 
for want of knowledge, and it is hoped that the facts here given may prove of 
practical value in preventing the spread of hydatid disease, although, according 
to Queensland hospital returns, cases of this disease are less frequent here than in 
the other colonies. Statistics show that onan average of twenty years 150 persons 
suffer and 14 die annually from this disease in the colony of Victoria alone ; 
and it is certain were the natural history of this parasite generally known and 
universally applied in everyday life, the prevalence of hydatids would be to all 
practical purposes extinct.* 
- Hvery squatter or sheep farmer knows what hydatid is when he sees it in 
his slaughtered sheep. He will often find attached to the liver, lungs, or 
elsewhere one or more bladders containing a greenish-yellow fluid, and these 
are what are known as hydatid cysts, which scientific men tell us are caused by 
a tapeworm which they call Tenia Echinococcus. It would be interesting to 
the curious to know how they get there. In order to understand the life 
history of the little tapeworm with such a name, we will imagine a cyst taken 
from # freshly killed sheep and thrown to a dog which is sure to be hard by. 
He swallows it with relish, and you naturally say he will have hydatids. Not 
so, however, for the dog never has hydatids ; but the eyst will, in most cases, 
j=) . . 
cause the presence of innumerable tapeworms, such as shown in accompanying 
Plate XLII. 
The cyst was full of Hchinococeus heads, or scolices, and, being freed from 
the cyst in the intestine of the dog, they at once commence operations on the 
intestinal walls by means of their many hooklets and suckers, of which there 
are four, and which can be distinctly seen under the microscope. See Plate XLIT. 
In 1866 (aceording to ‘ Proceedings of the Royal Society, Vol. XX., 
No. 86”) Nettleship carried out some experiments in connection with this 
tapeworm, and after administering to a dog some of the liquid from a eyst 
obtained from a freshly killed sheep found, when forty-seven days had expired, 
that his bowel contained no less than 8,800 specimens of Denia Echinococcus. 
This gives some idea of the enormous fecundity of the worm, and each one is 
capable of producing a hydatid cyst or tumour on finding a suitable “ host.” 
It is not from the sheep, as many think, that man becomes infected, but from 
water and dogs. 
Anyone who has witnessed the drafting of sheep or cattle on a hot day 
" will readily understand that those engaged in the operation must necessarily 
_ breathe in a quantity of dust, thus rendering themselves liable to pulmonary or 
_ * Captain E. C. Owen, of the Geological Survey Department, states that he has seen 
distressing cases of human beings suffering from hydatids in South Australia, owing to drinking 
infected water.—Ed. Q.4.J. 
