l6o WALTER LOUIS HAHN. 



same time so that the one wing is directly above the other ; the 

 sidevvise motion then continues far enough to bring the head 

 under the tail and the claws of the feet grasp the surface. If the 

 wall is too smooth to furnish a foothold the bat is in position for 

 immediate flight. Sometimes the position is only partially 

 reversed and the animal alights sidevvise. In this case the thumbs 

 support most of the weight. 



A flying bat can secure a foothold upon a horizontal surface 

 beneath which it is flying as easily as on a vertical wall. To 

 secure a foothold the bat throws its head downward and its feet 

 upward and forward till they touch the roof and the claws grasp 

 the supporting object. The quickness with which the momentum 

 of flight is checked is one of the nicest adaptations of a bat's 

 life. Only a slight roughness is necessary for the sharp curved 

 claws to secure a firm hold. I have seen a flying bat clasp and 

 hold a vertical number i6 wire that it accidentally struck. The 

 fore arms were placed behind the wire which was pressed against 

 the back as a man might hold a cane thrown across his shoulders. 

 A bat in flight can catch a rafter or similar object by a single 

 thumb, or by the claws of one foot. Metal, glass, polished wood 

 or stone are not rough enough to furnish support, but unplaned 

 boards, and rough limestone, furnish adequate foothold. 



When a bat launches into flight from a perch on the roof or 

 side wall, it always drops downward, spreading the wings as it 

 drops. It can launch into flight from the floor or other flat sur- 

 face, but it cannot rise vertically in the air from a resting position. 

 A bat which fell into an empty aquarium, i6 inches in diameter, 

 and the same depth, was unable either to climb its smooth sides 

 or to fly out of it. When caught in a dip net they are unable to 

 fly out of it, but must climb the sides and fly from the rim to 

 escape, a fact which makes it easier to capture them. 



Breeding Habits. 

 The reproduction of some of the European bats belonging to 

 the families Rhinolophid?e and Vespertilionidai has been studied 

 by several zoologists. Benecke ('79), Eimer ('79), Van Beneden 

 and Rollinat and Trouessart ('96), all state that copulation takes 

 place in late summer or autumn. The spermatozoa fill the lu- 



