PASS THE WINTER 143 



times forward, soiiietiiiies backward within the 

 range of about an inch. At first the plane of the 

 closed wings was perfectly horizontal, but about 

 the middle of January they became slightly 

 oblique, and the morning of the day it left its 

 station the obliquity was somewhat increased. 

 It was watched daily the winter through, and the 

 wings were always in the attitude taken at com- 

 plete repose in the summer. When on the last 

 day of February it left its station it took up an- 

 other, head downward on the cellar wall, near a 

 window where it caught the sun's rays a part of 

 the day, and here it remained motionless for five 

 days more, except for slight shifts as before, and 

 that when the sun struck it its antennae were 

 thrust forward and parted a little instead of being 

 ensconced between the wings. 



All hibernating butterflies, so far as known 

 at present, belong to the Nymphalidae and Papi- 

 lionidae, and almost exclusively to the Vanessini 

 and Khodocerini, neither Lycaenidae nor Hesperi- 

 dae being known to hibernate in the perfect stage. 

 Almost all the Vanessini of Europe as well as the 

 Brimstone butterfly (Colias rhamni) are known 

 to hibernate in the imago state, and in our own 



