SCIENCE AND INDUSTRY. 
fertility was much less, than in the case of the controls. In other words, not only 
did very few ticks mature on such animals, but there was also some impairment of 
the vitality as shown by the lessened number of-viable eggs (claim No. 8). We 
endeavoured to artificially infest a resistant animal to a moderate degree, but 
without success. 
We disagree with Mr. Hull’s opinion (claim No. 5) that the ticks on resistant 
cattle have developed on other animals and re-attached themselves to such 
resistant animals. In regard to the few ticks which Mr. Hull states (claim 
No. 7) are to be found in winter on such animals when other cattle are free, we 
believe the explanation to be as follows:—The cows which come under closest 
observation are the milkers, and, as a result of being in milk, such animals during 
winter frequently fall into somewhat low condition, which brings about a diminu- 
tion of their tick-resisting powers. On the other hand, resistant cows, when dry, 
seldom become infested. 
We took the temperatures of a number of resistant animals during the summer, 
and found them to be approximately normal. We think that a similar result 
would be obtained by registering ‘the temperatures during the winter also 
(claim No. 8). . 
Last year we called attention to the presence of tick resistance in cattle, and 
invited correspondence regarding the effects of breed, food, dipping, condition, &c. 
A number of replies were received from various districts. 
Brahmin cattle and crossbreds are more or less strongly resistant. In Queens- 
land, tick resistance is not confined to any one breed, though, apparently, more 
common amongst Jerseys and Jersey crosses, perhaps on account of the presence 
of fine short hair and rather oily skin. Individual animals of various other 
breeds, Shorthorn, Ayrshire, Holstein, Hereford, and their crosses may possess a 
marked resistance. We are inclined to believe that it is, to some extent, a matter 
of individual idiosynerasy. We think that food has an influence only to this 
extent, that animals in good condition are commonly less infested than those in 
poor condition. It may be urged that such animals are in good condition because 
they are not tick worried, but it is undoubtedly also true that an animal in good 
health is less liable to invasion owing to its natural resisting powers being then 
most marked. 
Resistant animals have been noted in a number of localities extending from 
the Atherton tableland to Springbrook plateau, more usually in the vicinity of 
scrub country—perhaps the more abundant fodder in such situations helping to 
maintain condition and resistance. 
Evidence has been collected in favour of, as well as against, the view that the 
application of arsenical solutions suppresses resistance. We are inclined to think 
that, provided the condition of the animals be not lowered by the treatment, sup- 
presssion or diminution of resistance does not happen. 
Transmissibility of resistanee—Mr. Hull claimed that it could be transmitted 
hereditarily, by vaccination, and by contact, i.e. that it could be naturally 
acquired. Mr. Pound’s observations did not uphold any of these claims. 
We have carefully collected all the evidence available in regard to the herds 
of Messrs. M. and F, Hull (Eumundi), Mr. Inigo Jones (Crohamhurst), and 
others. As a result, we believe that resistance in certain cases is a quality cap- 
able of hereditary transmission. This does not mean that all progeny of such 
cattle will be resistant. 
It is necessary to know how the parental stock acquired this peculiarity. We 
have not obtained sufficient information to allow us to state whether it is a 
Mendelian character. It is possible that certain cattle may really be “ sports” 
as far as resistance is concerned, and, in such cases, the quality would be trans- 
missible to a percentage of the offspring. We would like to obtain more informa- 
tion regarding the result of mating a resistant bull with resistant and non- 
resistant cows, so as to enable us to decide what part. (if any) heredity plays. 
There is considerable evidence in favour of the view that resistance can be 
transmitted to other animals by vaccination, i.e., by using some of the exudate 
(to be referred to later) from resistant cattle. We have not succeeded in so 
transmitting it to any of our experimental animals. 
Mr. Hull, when speaking of transmission by “contact,” means to infer that 
the condition is picked up naturally by means of the lary which hatch from 
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