186 PHYSIOLOGY. 



food, never discovered it, although several dogs had been 

 attracted to it by the scent. His next experiment was to 

 stick a young pig, and cover it over with leaves ; vultures 

 soon saw the blood, descended to it, and by this means soon 

 discovered the pig, while it was still fresh. The general 

 opinion of physiologists at present is, that birds of prey, 

 have not so acute a sense of smell as has been generally sup- 

 posed, and that they are guided chiefly by sight. 



19. It is stated by whale-fishermen, that in Greenland, 

 when a whale has been captured, although at the time 

 scarcely a single bird may be visible, yet in a short time, 

 immense numbers of gulls and other sea-birds hover about, 

 and hasten to the spot from every point of the compass. Al- 

 though these birds have the organ of smell, and conse- 

 quently the sense itself, largely developed, yet such facts may 

 be more satisfactorily explained, than by supposing that they 

 are able to smell the flesh of a dead whale, before putrefac- 

 tion has commenced, at a distance of many miles. A better 

 explanation cannot be given than is contained in the first 

 volume of " MacGillivray's History of British Birds." 

 Speaking of ravens gathering together in immense numbers 

 over a dead carcass, in explanation of the phenomenon he 

 remarks, " A single raven might first perceive the carcass. 

 Ravens have character in their flight as men have in their 

 walk. A poet sauntering by a river, a conchologist or fish- 

 woman looking for shells along the shore, a sportsman 

 searching the fields, a footman going on a message, a lady 

 running home from a shower, or a gentleman retreating 

 from a mad bull, move each in a different manner, suiting 

 the action to the occasion. Ravens do the same, as well as 

 other birds ; so those at the next station, perhaps a mile dis- 

 tant, judging by the flight of their neighbours that they had 

 a prize in view, might naturally follow. In this manner the 

 intelligence might be communicated over a large extent of 

 country, and in a single day a great number might assemble. 

 We know from observation that ravens can perceive an 



