82 MAMMALIA. 



(measuring 400mm. in extent) and differed from the adults chiefly 

 in being a Httle hghter colored. 



Zadock Thompson, in his paper upon the mammals of Vermont, 

 speaks thus of this species : " The only Vermont specimen, which 

 I have examined, and that from which the preceding description 

 was drawn, was sent me alive by my friend, David Reed, Esq., of 

 Colchester. It was taken at his place in Colchester, the latter part 

 of October, 1841, and was kept alive for some time in a large willow 

 basket with a flat cover of the same material. On opening the 

 basket, he was almost invariably found suspended by his hind claws 

 from the central part of the cover. When the basket was open, 

 he manifested little fear, or disposition to fly, or get away, during 

 the day time, but in the evening would readily mount on the wing 

 and fly about the room, and on lighting always suspended himself 

 by his hind claws with his head downward. He ate fearlessly and 

 voraciously of fresh meat when offered to him, but could not be 

 made to eat the common house fly."* 



The hour at which bats leave their retreats to begin their noc- 

 turnal excursions is governed, first, by the latitude, longitude, and 

 altitude of the locality, and the time of the year ; and, second, by 

 the character of the sky (whether clear or overcast), and the ex- 

 posure — those living along the southern and eastern borders of 

 woodlands, and in dark ravines, appearing earlier than those whose 

 hiding-places face the setting sun. In other words, the time at 

 which bats appear depends solely upon the degree of darkness. 



Hence it follows that their nightly exodus, in a given locality, 

 does not take place at a fixed period after the disappearance of the 

 sun ; for, during the first part of October, in this latitude, the dark- 

 ness is as great half an hour after sunset as it is an hour after three 

 months earlier. Therefore, in estimating the exact hour at which 

 bats are to be expected at any stated date, it is necessary not only 

 to consider the time the sun sets, but also to take into account the 



* Natural and Civil History of Vermont, 1842, p. 25. 



