1 88 WALTER LOUIS HAHN. 



one occasion a male, M. lucifiigtis, that I had marked by excising 

 the right tragus, escaped through a small crack under the door 

 into another room and thence to the outside through one of sev- 

 eral small holes. A few days later I found it in the cave and 

 brought it to the room again, and liberated it. 



It circled twice about the room and then dropped to the floor 

 near the door and started directly for the crack and escaped from 

 the house before I had a chance to stop it. Several days later 

 it was recaptured a second time and turned loose in the same 

 room. It started at once for the crack under the door. The 

 crack had now been stopped so that it could not get out, but it 

 ran about in that corner and for several days, whenever liberated 

 in the room it repeatedly went to the place where it had escaped 

 before. 



Certain bats, released in a room, show preference for alighting 

 in a particular spot while other individuals select other spots. 

 To illustrate, two bats were allowed to fly about a room lighted 

 by seven windows, all of which received about equally strong 

 Hght. Each bat alighted a number of times. One of them 

 selected the casing of window number two 12 per cent, of the 

 times and all other windows 12 per cent. Another bat selected 

 window number five 28 per cent, of the times and did not go to 

 window number two at all. Other instances could be cited illus- 

 trating the same point. The bats apparently find a place suitable 

 for resting by accident the first time and later return to it because 

 it is remembered. 



In experimenting with the bats in the cage, I found that they 

 also learned by accident to find the place where food was to be 

 obtained. When food was once associated with a certain place 

 the animals very quickly learned to go back there. After they 

 once learned the association it remained very persistently. In 

 the experiments with bat No. 2, outlined above, it was so per- 

 sistent that it prevented finding a new place in ten times the 

 number of trials required the first time. 



Memory in all of these cases is doubtless below the realm of 

 consciousness and akin to that which in man is rendered subcon- 

 scious through habit. Some sort of a memory is absolutely 

 necessary in order to make a sense of direction of any value to 



