THE LESSER HORSESHOE BAT 259 



males, and of the four females two were found on ist April at a 

 place where on 8th March there had been four males, while an- 

 other was hanging by herself in a separate part of one of the 

 caves. Similarly, of twenty specimens examined by Foot in 1859, 

 only one was a female. In corroboration, Mr Charles Oldham 

 writes me that of fourteen bats taken by Mr Coward and himself 

 from the Cefn Cave, near Denbigh, on 4th March, twelve were 

 males and two females. Further observation will no doubt 

 show whether the numbers of the sexes are unequal,^ or whether 

 Foot and Kinahan's experiences merely indicated that the adult 

 females had departed to bring forth their young apart from the 

 males. On the other hand, Messrs Coward and Oldham inform 

 me that they have seen males and females hanging together in 

 March, April, and on 2nd December. The idea that the males 

 outnumber the females, although at first sight improbable, has 

 gained in importance from Mr C. B. Moffat's^ suggestion — 

 based partly on a study of birds and insects in Ireland — that 

 fertility may decrease and females may become scarce as the 

 outskirts of the geographical range of a species is reached. It 

 is quite in keeping with the known disagreement between the 

 observations of continental and of British naturalists as regards 

 the number of young in bats. 



Another point suggested by the work of Foot and Kinahan 

 is that, like other species, the bats are not necessarily to be 

 found in the same retreats in summer as in winter. One cave, 

 that of Balliallia, was entered twice in March of two different 

 years and once in August, and, although tenanted by bats 

 in the former, was empty in the latter month. There is, 

 however, probably no definite rule about this habit, and the 

 reverse was found to be the case at Cheddar, Somerset, by 

 Mr Coward. 



Foot and Kinahan may be said to have demonstrated with 

 considerable accuracy the general features and characteristics 

 of the cave-life of these bats ; in fact, the only point in regard 

 to which later observers have shown them to be in error is in 

 the supposed necessity for woods and plantations in the neigh- 

 bourhood of the bat-caves. Both Mr Coward and Mr Oldham 



' It is suggested by E. HoUis for Devonshire, see Zoologist, 1907, iir. 

 2 Irish Naturalist, 1907, 140-144. 



