THE COMMON MOLE, MOLDWARP OR WANT 35 



earliest personal record for a foetal litter is 1 3th April, and he 

 has notes of young found in the nest from 24th April (on 

 the authority of a mole-catcher), 4th May (about seven days 

 old, his earliest personal record) to 25th June (his latest 

 record). The latter were almost ready to leave the nest, and 

 were, therefore, at least three weeks old. 



Practically all the young, therefore, are born within the 

 period commencing about 24th April and ending about 

 4th June. 



The fact that the runs made by the two sexes are distinguish- 

 able, shows that they usually live apart ; but during the breeding 

 season the males leave their own long straight runs, and 

 are found in the winding tunnels which are the work of the 

 female. Here, no doubt, pairing takes place ; as it may, 

 possibly, also above ground, as once observed by a keeper who 

 informed Mr Adams. 



Very similar results have been independently obtained by 

 Mr Evans, working in the Edinburgh district, and by Mr 

 Cocks in South Buckinghamshire. Mr Evans found embryos 

 from the 7th April onwards, and, on the 24th May, young 

 which he judged to be about a week old. Mr Cocks reports 

 embryos from 14th April to 20th May. On the 21st May 

 two young ones were captured, of approximately three-quarters 

 full size, so that they were probably born about the ist of 

 May ; and in 1877 two litters (of four and three) were found on 

 the Berkshire side of the Thames at Bisham on 28th April. 

 Mr Cocks remarks that, whereas the embryos examined in 

 April showed only a very little variation in size, some found 

 on 14th May were younger than those of a month earlier, 

 and others found on 20th May only equalled the size of a 

 foetal litter found on i8th April, or over a month previously. 



Calculating that the period of gestation is four weeks, or 

 rather more, Mr Adams thinks that "the female would not have 

 time to breed twice within the period mentioned during which 

 young are found, even if she were in condition to do so, which 

 she is not. Moreover, these limits are not those of the same 

 year or locality, so they may be fairly curtailed, and a month 

 of courtship may be presumed to be the limit of the Mole's 

 capacity." On the other hand, there may be a few excep- 



