156 WALTER LOUIS HAHN. 



have found that the animals do not, as a rule, pay any attention 

 to worms held near them so long as they are quiet. But when 

 the worms begin to wriggle the bats at once become excited and 

 begin to snap at them. This happens when they are not touched 

 by the worms and when the latter are out of the range of vision. 

 It seems improbable that touch is the sense here aroused. The 

 food must have been perceived by the tactile organs being stimu- 

 lated by air currents set in motion by the moving worms. 



It is said that bats use the interfemoral membrane, which the 

 flying animal carries curved downward and forward under the 

 body, as a sort of scoop in which insects are caught. It is pos- 

 sible that food is thus secured at times, but it is more often seized 

 in the mouth. However, the membrane is used as a pouch into 

 which the bat thrusts its head when it has an insecure hold on 

 an insect. The membrane thus serves as a pouch to prevent 

 dropping the food and also serves as an object against which the 

 struggling prey can be pressed while a firmer hold is being 

 secured. 



Observers (Whitaker, '06 ; Grabham, '99), who have studied 

 the habits of various European species of bats agree that they 

 drink while on the wing, flying over a body of water and dipping 

 down to its surface to drink. I have observed the same habit in 

 M. hicifiigns ; it probably alights to drink also. When in cap- 

 tivity this species learns readily to come to a small cup of water 

 placed on the floor of its cage. The animal gets up on the edge 

 of the dish, resting on its wings and body and bracing with its 

 feet. Often it dips a part of the forearm and wing into the water. 

 The lower jaw and tongue are thrust in, the mouth is filled with 

 water and, generally, but not always, the head is raised to its 

 normal position and the water is taken down in a succession of 

 rapid swallows. On the whole, the method of drinking resembles 

 that of a young chick, except that the head is not lifted so high. 



If the conclusions given above as to the manner of perceiving 

 food are correct, it is obvious that water must be perceived in some 

 other way, since it is obtained where it is relatively stationary and 

 noiseless. On two occasions I have seen bats in the laboratory 

 apparently attempt to drink while flying. On the first occasion 

 there was an aquarium of running water in the room. The bat 



