A New System for Preventing Collisions at Sea 



HEAD OF THE TRUE VAMPIRE BAT. 



This bat does not pursue insects in the air and does not fly about in total dark- 

 ness ; the sensitive organs, both on the nose and in the ear, are in a rudimentary 

 form and probably are of very little use, but the eyes are large, which show that 

 it depends upon the sense of sight instead of the sixth sense. 



HEAD 



THE GREY FRUIT BAT. 



This bat does not inhabit caves or dark places, does not fly about on dark 

 nights, and lives exclusively on fruit. It depends altogether upon its large 

 eyes and moderate-sized ears, the organ of the sixth sense being completely absent. 

 All bats with a highly developed sixth sense are provided with extremely small 

 eyes, and no bat with large eyes has a highly developed sixth sense. 



