466 MURID^— ORCADENSIS 



At that time, of sixteen females trapped, several were pregnant 

 with from two to six foetuses.^ Others taken by Mr Godfrey 

 on 8th and 9th August contained foetuses "the size of peas." 

 Mr Robert Drane^ has bred these mice in confinement, and 

 states that six received in August 1904 increased to sixteen 

 by October. There was then a cessation of reproduction until 

 28th February 1905, when two of the females gave birth to 

 litters of three and four young respectively. Mr Drane 

 definitely ascertained that the period of gestation is, as in other 

 species, twenty-one to twenty-two days (one instance). The 

 young of one litter opened their eyes and emerged from the 

 nest to nibble lettuce leaves on. the 12th day. At eighteen 

 days old they were independent of their mother, who still, 

 however, exercised parental authority and drove them home 

 peremptorily if she considered them in danger. 



Mr Kinnear found the mice fond of the roots of a common 

 rush,^ to obtain which they burrow under the tufts. Mr W. R. 

 Ogilvie-Grant took the Sanday form with baits of cheese and 

 bulbs of. yellow crocus. In captivity their favourite food is 

 grass ; next, carrots. Their intelligence appears to be inter- 

 mediate between that of the Bank Mouse and the Common 

 Grass Mouse, but reports of their amiability vary, no doubt 

 according to the manner in which they were treated. They 

 may bite if roughly handled, will attack fresh members of their 

 own species when first introduced to their cage, and sometimes 

 behave with great brutality amongst themselves.'* Females 

 with young must be isolated to protect the litter from the 

 attacks of strange males. 



Mr Millais found that his mice became inactive during cold 

 weather. 



Like other Grass Mice, the Orkney Mouse is very palatable. 

 Every bird and beast seems to eat it, and dogs devour it 

 greedily.* 



1 One contained two ; three contained four ; one contained six. 



^ Field, 18th March 1905, 465 ; also in Millais. 



^ Determined by W. Evans as /uncus squarosa. 



* Drane, op. cit. 6 T. E. Buckley, op. cit. supra, p. 49. 



