320 Transactions. — Zoology. 



rapa district ; but it does not seem to spread — most probably 

 owing to the absence of other carnivorous animals in -which 

 the hydatid exists in the tapeworm stage. The animals that 

 prey on the rabbit in the country I speak of are the wolf, the 

 kit-fox, and the common fox ; so that if it is due to the fluke it 

 is probable that it is from one of these animals that the disease 

 is derived. James Hectok. 



Colonial Museum, 30tli December, 1887. 



The Hon. the Minister of Mines. 

 I HAVE already reported on these papers to the Joint Eabbit 

 Committee. ' 



The disease described by Mr. McBeath (p. 11 j as so fatal 

 to rabbits is the same that I referred to in evidence given on 

 the subject in 1872. It is not a constitiitional disease, as Mr. 

 McBeath states, nor one affected by climate, as Mr. Bayley 

 suggests, but is due to some form of an internal parasite (pro- 

 bably the Cccnurus) that gives rise to what are known among 

 the warreners of Norfolk as " bladdery rabbits." 



As I previously reported, in 1857-59 I have seen the rab- 

 bits wholly destroyed by disease over large districts of 

 western Canada, and have in consequence been myself nearly 

 starved along with the Indians, just as described by Mr. 

 McBeath. There is reason to believe that this " bladder- 

 worm " is one stage in the development of a kind of tapeworm 

 that infests the lynx, fox, and perhaps other carnivorous 

 animals that prey on rabbits. This double form of existence 

 explains the periodicity of the murrain. 



The chain of circum.^tances is somewhat as follows : — First 

 period : Babbits increase greatly until they are in swarms. 

 Second period : Lynxes and foxes are attracted to, and thrive 

 in, the district, and infect the rabbits. Third period : The 

 rabbits die off, and the lynxes and foxes clear out to other 

 districts in search of food. Fourth period : A few remaining 

 rabbits commence to breed, and the first period recurs. 



As the rabbit is nmch shorter-lived, more rapidly ma- 

 tured, and greatly more prolific than the fox or lynx, the latter 

 can only be saved from destruction by migration. The fox 

 and lynx do not therefore keep the rabbit in check merely by 

 preying on them, but in a far greater degree by the convey- 

 ance of the disease that causes the murrain among the 

 rabbits. In a somewhat similar manner the scab-insect of 

 the cat is the same that infests the rabbit with fatal results — 

 attention to which as a means of checking the rabbit-pest 

 has been lately recalled by Professor Watson, of Adelaide ; 

 but it would be w'ell to await the result of experiments that 

 are being made to ascertain if this scab-insect is specifically 

 distinct from that of the sheep. 



