VESFERUC-.O XOCTIVAGANS. 19^ 



killed on the first evening of their appearance averaged 90mm. in 

 lencrth by 261mm. in stretch, but weighed only half as much as 

 thetr parents. The adults average about 104mm. in length b)- 

 302mm. in stretch. When on the wing the young may be dis- 

 tinguished from the old by the weakness and hesitancy of their 

 fliaht, rather than by the difference in size. The young are much 

 more beautiful than the adults, and they alone possess the perfect 

 silvery tips to the hairs from which the species derives its name. 

 Even before going into winter quarters their soft silvery backs 

 have given place to the grizzly coats that characterize the adults. 

 My^esteemed friend, Mr. William Brewster, has kindly favored 

 me with the following very interesting account of a colony of bats 

 that he discovered during an ornithological excursion into the ex- 

 tensive coniferous forests of western Maine : — 



"On June 18, 1880, I was searching for woodpecker's nests 

 among the stubs that line the shores of Lake Umbagog, when I 

 notict^d a small ragged-looking hole about two feet above the water 

 in a trunk that stood well out on the flooded meadows. I should 

 hardly have turned aside to examine it had I not fancied that I saw 

 something move at its entrance ; accordingly, paddling to the spot, 

 I struck the tree sharply with the butt of an axe. The blow was 

 followed, not by the appearance of a woodpecker's or nuthatch's 

 head, as I had expected, but by an outbreak of shrill squeaking 

 sounds that seemed to come from every part of the interior. A^ 



have been borr^hhTf^ei^iM^ The single one, a male, weighed iioo milligrammes, 

 and measured 43mm. in length by ygm-"- i" extent ; the cord measured 20nam and the placenta 

 10x14mm One of the other females contained twins, both of which were females ; one of them 

 weighed 13S0 milligrammes, measuring 41mm- i" length by 72mm. in stretch; cord l8mm.; 

 nlacxMUa qM4mm. The other weighed IIOD milligrammes, and measured 39x6Smm. ; cord 17mm. ; 

 placenta 8x13mm. That the young are brought forth in the southern part of the State at about the 

 same date as with us is evidenced from the following. Dr. A. K. Fisher states that a female wh.ch 

 he killed at Sing Sing, in Westchester County, June 24, 1S81. "contained two young, well de- 

 veloped and probably would have been delivered in a few days. The young each weighed 1.45c 

 milligrammes. On removing the amnion the cars of one of the young bats became erect. 1 h e 

 nlaccmta of this species is different from that of the Little l>.rown Bat ; inste.ad of bemg circular it 

 is elliptical, measuring 10 by 15 millimetres. The placenta^ 'were attached to the posterior wall of 

 the uterus near the summit of e.ach cornu. The umbilical cor<l measured twenty millimetres in 

 length." (Forest an.l Stream. Vol. XVI. No. 25, July 21. i88r. p. 490-) 



