HEARING. 31 



birds in these respects. This is easily proved by the 

 simple experiment of trying the effect of various 

 sounds upon the birds, taking care to have the cause 

 thereof concealed from their view. We have, for 

 example, caused a dog to bark behind a wall on the 

 other side of which geese were feeding, without their 

 appearing to take any notice of it, no more than they 

 did when we shouted aloud on purpose to alarm 

 them. When the dog, however, was brought into 

 view, they took immediate alarm *. We should there- 

 fore be inclined to infer that the hearing of the goose 

 is by no means so very quick. The structure of 

 the ear again would lead to the same conclusion ; 

 although it does indicate quicker hearing than that 

 of the duck, the cavity of the drum as well as other 

 parts of the organ being much more capacious in the 

 goose. Its smell also, though undoubtedly acute, as 

 might at once be concluded from the capacity of the 

 nostrils, is more adapted for ascertaining the quality 

 of its food than for giving intimation of distant 

 danger. Accordingly we never see a goose elevating 

 its head and snuffing the air as dogs, deer, and other 

 animals are observed to do, for the apparent purpose 

 of discovering distant friends or enemies. We should 

 therefore reject the explanation given by Lucretius 

 and Isidore. 



The correct view of the matter, as it appears to us, 

 was first hinted at by Albertus Magnus, who says 

 the goose sleeps so lightly, that it is awakened by the 

 least noise f. The profoundness of sleep indeed is 

 found to be in proportion to the quantity of brain and 

 the rapidity of circulation, and both these being in 

 birds unfavourable to sleep, renders them very easily 

 awakened J. The hearing also, according to M. 

 Cabani, though it is not so "soon overpowered by 



* J, R. f Apud Aldrovandi Ornith. iii. 46. 



I Macnish, Philosophy of Sleep, p. 40. 



