Biology of H. cmnabarlna 529 



progeny of 2 $ (N. 2452) taken from cattle in Winnipeg, Canada, and 

 for which I am indebted to Mr J. R. N. Harrison. The ticks were 

 raised on rabbits in experimental cages at room temperature (about 

 15''C.) in the laboratory. The ticks were kept in an incubator at 

 30^ C. during metamorphosis. 



The recently emerged larvae were placed on a rabbit on 27. xi. 

 1913: 



No. of gorged larvae collected 

 on successive days 



The first nymphs emerged on 11. xii. 19i:>, i.e., metamorphosis from 

 larva to nymph lasted 10-11 days at 30" C. (86" F.). On 6. I. 1914 the 

 nymphs (100) were placed on a rabbit: 



The first adults emerged on 10. ii. 1914, i e., metamorphosis from 

 nymph to adult lasted 28 days at 30" C. 



Mv results accord with those of the American authors, but the 

 nymphs remained longei- upon the host. 



Longevity of unfed ticks. 



Larvae which emerged 7. xi. 191:5, died after 43 days. Nymphs 

 which emerged 11. xii. 1913, died after 34 days (at room temperature). 



