COMMON BAT, PIPISTRELLE OR FLITTER-MOUSE 121 



precisely as in the case of other bats. On the other hand, Mr 

 Whitaker suggests that pairing may take place during the 

 latter half of May, at which time he has noticed bats 

 chasing each other, a fact not necessarily evidence of pairing/ 

 Unfortunately, no precise observations exist for Britain. It 

 is, however, certain that the date of birth varies a good deal, 

 at least from late June" to early August, but it is never, so 

 far as is known, so early as to be inconsistent with Messrs 

 Rollinat and Trouessart's results. Thus Mr H. Lyster 

 Jameson,^ when visiting Bohoe Church, Ireland, on nth 

 July, found a number of young Pipistrelles, from a few 

 days old to half- grown individuals, crawling about the 

 floor of the church, having fallen through a hole in the 

 ceiling. As regards July births, four captive females, in 

 the possession of Mr Whitaker, produced their respective 

 young on the 2nd, loth, i8th, and 19th ; while Mr Coward 

 found an embryo nearly ready for birth in a female killed on 

 the 4th of the same month. The earliest of these would, no 

 doubt, have been born in June, and the possibility of early 

 births is further strengthened by the capture of a young one 

 on the wing on 9th August at Exeter,^ and of another at 

 Kilmanock, County Wexford, Ireland, on the 13th. Allowing 

 seven weeks each for gestation and rearing, the birth of these 

 two bats must have taken place some time between 21st and 

 25th June. Their southern habitats sufficiently account for 

 the early date, and it is interesting to note that the Wexford 

 bat was fully grown, although certainly immature. 



In two of Mr Whitaker's bats the known period of gestation 

 was not less than forty-one and forty-four days, and in a third it 

 probably reached forty-nine. The mother was captured between 

 27th and 31st May, had for companions two males of 

 her own species, and when she died on 14th July was found 

 to contain a small embryo, "probably not more than half- 



^ See his " Notes on the Breeding Habits of Bats," Naturalist, 1905, 325-330. 



- A statement by J. J. Briggs {Zoologist, 1848, 2278) that the bats in Melbourne 

 Church, Derbyshire, "bring out their young about June 17th," is unfortunately some- 

 what indefinite as regards the exact species. 



^ Irish Naturalist, 1896, 95. 



* Now in the Exeter Museum, and kindly submitted to me for examination by 

 Edwin Hollis. 



M 



