210 LEPORID^— ORYCTOLAGUS 



The Rabbit is certainly polygamous when abundant. The 

 doe is evidently polycestrous, with a long sexual season, and her 

 several litters may appear during winter as well as in summer, 

 but much less frequently between September and December, 1 or, 

 in cold northern localities, between September and February. 2 

 The period of gestation lasts for thirty days, and from three to 

 five or six young are most usually brought forth at a time. 

 Instances are known in which the number found together in a 

 nest amounted to eleven, 3 and even to fourteen, 4 but possibly 

 the larger numbers may have been due to superfcetation, or to 

 a combination of the litters of two mothers. The doe is 

 believed to commence breeding when six months old, but since 

 a rabbit becomes fully grown in about three months, and the 

 domestic forms breed at the latter age, that period may be 

 regarded as marking the advent of sexual maturity in wild does 

 also, although no definite observations appear to have been 

 placed on record. 



Since the breeding season, in the south at all events, lasts 

 nearly throughout the year, and since several litters may be 

 born of one mother in a year, the number of young in each case 

 depends on the season. As the result of over four years' 

 observations in South Buckinghamshire, Mr A. H. Cocks finds 

 that the average number in a litter increases from between two 

 and three in October to nearly six in June, and then drops 

 again to October. The average is five (plus different fractions) 

 for March, April, May, June, and July. The rise or drop is 

 gradual, except between September and October (downwards) 

 and November and December (upwards). The ratio of the 

 number of litters corresponds fairly well with the monthly 

 average of young per litter, being probably greatest between 

 March and June, and the reverse in October and November, 

 but the proportional rise and fall is much greater. Mr Cocks 

 met with eight young on four occasions in May, June, and 



1 For an instance of midwinter young under extremely unfavourable circum- 

 stances, see J. A. Harvie-Brown's account (Zoologist, 1867, 604) of a breeding-nest 

 composed entirely of rabbit's wool placed under four inches of frozen ground at 

 Dunipace, Stirlingshire, Scotland, in early January. 



2 Simpson, op. cit., 20. 



3 E.g., E. R. Alston in Bell, ed. 2, 345 ; once at Kilmanock. 



4 George Sim, 72, on the authority of a keeper. 



