28 A HISTORY OF 



ran be expected in animals whose eyes are almost as large as their 

 brain ? However, though they fall below quadrupeds in the scale of 

 nature, and are less imitative of human endowments ; yet they hold 

 the next rank, and far surpass fishes and insects, both in the structure 

 of their bodies, and in their sagacity. 



As in mechanics the most curious instruments are generally the 

 most complicated, so it is in anatomy. The body of man presents the 

 greatest variety upon dissection ; quadrupeds, less perfectly formed, 

 discover their defects in the simplicity of their conformation ; the 

 mechanism of birds is still less complex; fishes are furnished with fewer 

 organs still ; while insects, more imperfect than all, seem to fill up the 

 chasm that separates animal from vegetable nature. Of man, the most 

 perfect animal, there are but three or four species ; rf quadrupeds, 

 the kinds are more numerous ; birds are more various still ; fishes yet 

 more ; but insects afford so very great a variety, that ihey elude the 

 search of the most inquisitive pursuer. 



Quadrupeds, as was said, have some distant resemblance in their 

 internal structui e with man ; but that of birds is entirely dissimilar. 

 As they seem chiefly formed to inhabit the empty regions of air, all 

 their parts are adapted to their destined situation. It will be proper, 

 therefore, before I give a general history of birds, to enter into a slight 

 detail of their anatomy and conformation. 



As to their external parts, they seem surprisingly adapted for swift- 

 ness of motion. The shape of their body is sharp before, tr pierce 

 and make way through the air ; it then rises by a gentle swelling to 

 its bulk, and falls off in an expansive tail, that helps to keep it buoy- 

 ant, while the fore-parts are cleaving the air by their sharpness. From 

 this conformation, they have often been compared to a ship making 

 its way through the water ; the trunk of the body answers to the hold, 

 die head to the prow, the tail to the rudder, and the wings to the 

 oars ; from whence the poets have adopted the metaphor of remigium 

 alarum, when they described the wavy motion of a bird in flight. 



What we are called upon next to admire, in the external formation 

 of birds, is the neat position of the feathers, lying all one way, answer- 

 ing at once the purposes of warmth, speed, and security. They mostly 

 tend backward, and are laid over one another in an exact and regular 

 order, armed with warm and soft down next the body, and more strong- 

 ly fortified, and curiously closed externally, to fence off the injuries of 

 the weather. But, lest the feathers should spoil by their violent attri- 

 iion against the air, or imbibe the moisture of the atmosphere, the 

 animal is furnished with a gland behind, containing a proper quantity 

 of oil, which can be pressed out by the bird's bill, and laid smoothly 

 over every feather that wants to be dressed for the occasion. This 

 gland is situated on the rump, and furnished with an opening or ex- 

 cretory duct ; about which grows a small tuft of feathers somewhat 

 like a painter's pencil. When, therefore, the feathers are shattered or 

 rumpled, the bird, turning its head backwards, with the bill catches 

 hold of the gland, and pressing it, forces out the oily substance, with 

 which it anoints the disjointed parts of the feathers ; and drawing them 

 out with great assiduity, recomposes and places them in due order; 

 by which they unite more closely together. Such poultry, however, 



