COMMON BAT, PIPISTRELLE OR FLITTER-MOUSE 107 



It has probably found its way to every island of any extent, and 

 has been identified from Orkney (Spence, Ann. Scott. Nat. Hist., 1909, 

 47), Islay, Mull (Alston; Gilmour, Mag. cit., 1897, 191; Russell), the 

 Outer Hebrides (Harvie-Brown and Buckley), Man (where Kermode 

 considers it common, and whence Oldham has received a specimen), 

 Anglesey (Coward and Oldham), Wight (More; Wadham), and the 

 Scillys (Clark). It is probably the species which has been observed in 

 Shetland (hibernating in a peat stack, Tulloch, Mag.cit., 1904, 125 ; also 

 Millais), Jura(by myself), the Blaskets (Kane, Irish Naturalist, 1897, 88), 

 and other Irish islands, and at such outlying lighthouses as the Fastnet, 

 Rockabill, and Blackrock, Co. Mayo (Barrington, Migration of Birds, 

 284). It is common in all the Channel Islands (Bunting). So diverse 

 are its haunts that, although reaching an altitude of at least 750 feet at 

 Carmichael, Scotland (Watt), it finds a sustenance equally well in the 

 heart of the largest towns, even of London (Rendall, Zoologist, 1888, 24). 



Distribution in time : — Pleistocene remains from Ightham Fissure, 

 Kent, have been provisionally referred to this species by E. T. Newton 

 {Quarterly Journ. GeoL Soc, ist May 1894, 193). 



Period of gestation :— At least forty-four days (A. Whitaker, 

 Naturalist, 1907, 74, and in lit), but see under NocTULE. 



Number of young and breeding season : — The (in Britain) single 

 young one is born sometime between late June and early August. 

 Continental naturalists write of two young ones at a birth as not unusual. 



Description : — The form and general characteristics of P. pipistrellus 

 are those of its genus. The ear when laid forward reaches to a point 

 about half-way between eye and nostril. The exterior margin is more 

 deeply notched than in Nyctalus (Fig. 2, No. 3, p. 7; for head, see 

 Plate XL, Fig. 4, p. 140). 



The fur is long and thick, and almost hides the round, very small 

 eyes ; above the anterior angle of each is a small wart, from which 

 grow a few black hairs ; on the forehead a transverse tuft of long 

 upright hair alters the apparent contour of the face, making the fore- 

 head appear comparatively prominent, whereas it is in reality depressed 

 in contrast to the well-developed glandular prominences of the muzzle. 

 The furring of the wing resembles that of Nyctalus, but there is no carpal 

 band. The interfemoral membrane is furred above nearly as far as a 

 line drawn between the ankles when the tail and interfemoral membrane 

 are extended ; beneath, the fur passes on to the membrane only at the 

 root of the tail and along the inner side of the thighs, about half the 

 remaining portion being covered with fine short hairs extending princi- 

 pally along the tail. 



The colour of the upper side varies between " mars brown " and 

 "Prouts brown," with tendencies towards "wood brown'' and even 

 " clove brown " ; the lower side is lighter. The hidden portions of the 



