PIPISTRELLE. 39 



expand its wings and take flight. This was repeated by 

 a single individual, in the library of the author of the 

 first edition of this work, several times in the course 

 of an hour, and without the slightest appearance of 

 difficulty or effort: it was, on the contrary, evidently 

 a natural and usual action. The same habit was ob- 

 served in V. Nattereri and Plecotus auritus. In its pro- 

 gression on the ground, however, it differs considerably 

 from some others, and particularly from the last-men- 

 tioned species. The Plecotus, in crawling or walking 

 along a horizontal surface, has the anterior part of the 

 body considerably elevated above the ground, and its 

 progression is effected by a succession of abrupt im- 

 pulses or leaps of one side after the other ; whilst the 

 Pipistrelle, which never raises the head from near the 

 ground, runs along in an almost prostrate position, but at 

 the same time with more celerity and freedom than any 

 other that we have had an opportunity of observing. In 

 climbing it evinces a corresponding degree of agility. 



But there is one circumstance of considerable interest 

 which we have observed in this species, which does not 

 appear to have been before noticed, and which, it is 

 probable, appertains in a more striking manner to 

 others. It is the prehensile character of the ex- 

 tremity of the tail. A small portion of the tail in 

 this and in most other species of this family is ex- 

 serted beyond the margin of the interfemoral mem- 

 brane. Not only does the animal employ the tail in 

 horizontal progression in which case it assists in throw- 

 ing forward the body, by being brought into contact with 

 the ground on either side alternately, corresponding with 

 the action of the hinder foot on the same side, but in 

 ascending and descending a rough perpendicular surface, 

 this little caudal finger holds by any projecting point, 



