70 VESPERTILIONID^— NYCTALUS 



then standing at 40" Fahrenheit, and according to Mr Steele 

 Elliott,^ it flies commonly in Worcestershire towards the end 

 of that month, the earliest which he ever saw on the wing having 

 been active on 22nd February. Mr Oldham has detected 

 it in flight on i8th, 20th, 8th, and iSth March in the 

 years 1902 to 1905 respectively. In autumn the flying season 

 seems to terminate ordinarily towards the end of October, 

 during which month Mr O. V. Aplin has seen ^ it out in 

 Oxfordshire in very cold weather, both foggy and frosty. 

 More than one writer has reported ^ the flying of Noctules so 

 late as the second week of November, but probably Mr G. T. 

 Rope's observation * of the 28th of that month, and Mr Aplin's, 

 as quoted by Mr Millais, of 3rd December, are the latest 

 recorded. 



So far as I am aware, Dowker^ was the first Englishman 

 to point out that the evening flight lasts only for about 

 an hour. He watched the bats emerging from their winter 

 quarters under the gable of his house early in May and 

 June. The weather seemed to have little influence on their 

 activity once they were in full flight, but at first only a 

 portion of the colony appeared to be active enough to 

 take wing. He counted only fourteen on ist May, but 

 the number increased to sixty - seven on 4th June and 

 to one hundred and twenty on the 12th, after which they 

 appeared in decreasing numbers, until in the middle of the 

 month only one was visible. The time of their appearance 

 varied from 7.50 to 8.15 p.m., the return of the first taking 

 place at about 9, when, if many happened to be out, they 

 came flying round their home like a cloud of bees, awaiting 

 opportunity to enter. With unimportant variations, Dowker's 

 statements are closely corroborated by Mr Booth,® who describes 

 the appearance of the members of a large colony in small 

 parties in the late April and early May evenings ; their steady 

 increase, until in early June the numbers leaving nightly became 

 almost incredible, and later their rapid decrease, until in July 



' Zoologist, 1904, 455. 2 Ibid., 1885, 344. 



^ E.g., Forrest, Steele Elliott, Henry Laver (specimen obtained on the loth), 

 Millais. 



* Zoologist, 1891, 167. ^ Ibid., 1890, 217 ; 1891, 305. " Ibid., 1905, 427-429' 



