60 EVOLUTION OF LIFE. 



been transported to different and remote partfc 

 of different countries, and, upon being released 

 from their confinement, have returned, with a 

 letter round their necks, to the very spot, 

 whence they had been transported. The olfac- 

 tory poivers of dogs of particular species, are 

 equally certain ; they are enabled to follow 

 with the greatest rapidity, the game which 

 they pursue, by the effluvia on the surface ; 

 and, however, extraordinary it may appear, I 

 have been assured, that a dog belonging to a 

 regiment, which it was accompanying, in its 

 march from Glocestev to Greenwich, and which 

 had been stolen in the Borough, after making 

 its escape, returned, two days afterwards, to 

 the head quarters at Glocester, where it was 

 received by an officer, who had been left be- 

 hind. It is unnecessary for me to go into a 

 more particular detail of the power which the 

 organs of sense, in animals, possess ; it would, 

 however, lead to this general conclusion, that 

 they are far more active and acute than they 

 are in the human species. 



Without the intervention of these organs of 

 sese, it is impossible that animals could ob- 

 tain any knowledge of external objects ; with- 

 out the eye, that they could obtain any know- 

 ledge of color ; without the ear, of sound ; 

 without the olfactory sense, of flavor ; without 

 the tongue, of sapid bodies ; and, without the 



