184 PHYSIOLOGY. 



reject instinctively, every thing which would prove noxious 

 or disagreeable. It is not, however, infallible even in the 

 brute creation ; for we see the flesh-fly attracted by a certain 

 species of mushroom which admits a cadaverous odour, simi- 

 lar to putrid flesh ; in these they deposit their eggs, which, 

 when hatched, perish for want of suitable food to nourish 

 them. 



14. A singular custom, which prevails among shepherds 

 in some countries, shows that the sheep is more under the 

 guidance of smell than sight or any of the other senses. 

 " When a lamb has died," says Aitkin, * the shepherd 

 wishes to put to the ewe another lamb that may have lost its 

 dam ; if she refuses to foster the stranger, he is sure to suc- 

 ceed by stripping off the skin of her own offspring, and tying 

 it on the back of the stranger, that she may smell the skin ; 

 she then entertains and treats it as her own. In this case 

 she neglects the sense of sight, for nothing can be more un- 

 couth than the object of her affections ; neither does she 

 attend to the evidence afforded by hearing ; however unlike 

 the bleating of the foster lamb may be to that to which she 

 was first accustomed, her smelling is satisfied, and she is con- 

 tent." The same practice succeeds with the cow. 



15. In the elephant, the tapir, and the hog, as well as in 

 oxen, sheep, deer, and antelopes, we find the cavities of the 

 nose very capacious, and the surface of the pituitary mem- 

 brane vastly extended ; and accordingly the sense of smell is 

 proportionally acute. In France it is customary to employ 

 the hog to hunt for truffles, a species of edible mushroom 

 which grows at some distance below the surface of the 

 ground. By the sense of smell alone, he is accurately 

 guided to the spot where one is growing, and begins to turn 

 up the earth with his snout, in order to get at it. The vege- 

 table hunter, however, anticipates him, and driving away the 

 animal, digs down, and appropriates it to himself. In this 

 way he secures, in a short time, sufficient for a family din- 

 ner. 



