528 MURID^— APODEMUS 



Until the young were three weeks old, the mother frequently 

 carried them back to the nesting-box, usually lifting them by 

 the side of the belly, midway between the fore and hind legs, 

 the mother's erect head raising them completely above the 

 ground. The dam soon discovered that her load must be 

 changed at the narrow entrance to the nesting-box, and so 

 dropping the young ones outside, she entered, and turning 

 round dragged each baby in head foremost. Occasionally the 

 parents attempted to drag older children into the nest. 



Mr Barrington's remarks are confirmed by Dr Henry 

 Laver,^ who observed copulation, and found that the periods 

 of gestation and oestrus seem to be respectively twenty-four to 

 twenty-five and six days, copulation taking place a few hours after 

 the birth of a litter, and six days after a previous ineffective pairing. 



It must be noted that Mr Barrington's observations are 

 in one or two respects abnormal; The original mice having 

 been taken in the autumn, did not produce young until the 

 following spring, when five and a half months old. Had they 

 been the young of early spring litters, they might have been 

 expected to breed when younger. 



A female in the possession of Monsieur Fernand Lataste, 

 being deprived of her young, imposed upon herself the task 

 of rearing a strange baby, and Mr F. H. Parrott informed 

 Mr Cocks that one he had reared a htter of Grass Mice. 



As a result of his examination of thirty-four litters, Mr 

 Adams thinks that the average number of young per litter 

 is about five ; he has seen one litter of nine young, three 

 of seven, five of six, thirteen of five, nine of four, two of 

 three, and one of two. Mr Adams has found young in every 

 month of the year excepting January, and, very curiously, June 

 and July. 



The breeding habits probably resemble those of the House 

 Mouse ^; the young cling to the mother's teats just Hke other 

 mice,^ and it is extraordinary to what a pace she attains with 



' Field, 19th August 1905, 378 ; and in lit. ^ Lataste. 



^ Gilbert White, Letter lii. to Daines Barrington, 26th March 1773 ; R. M. 

 Barrington, op. cit; J.J. Briggs, Zoologist, 1856, 5311 (? species doubtful); Victor 

 Fatio witnessed a female ploughed out of the ground with the young attached to her 

 hair and tail (p. 213). The famous incident which made Burns write of a "wee 

 sleekit, cowrin', tim'rous beastie"may be recalled. See also Rope, Zoologist, 1873, 



