DR PETTIGREW ON THE PHYSIOLOGY OF WINGS. 



387 



area of the wings decreases as the size and weight of the body increase. M. 

 de Lucy has tabulated his results, which I subjoin.""' 



Insects. 



Birds. 



Names. 



Referred to the 



kilogramme. 



=21bs.8oz. 3dwt. 2gr. 



Avoird. 

 = 2 lbs. 3 oz. 4-428 dr. 



Names. 



Referred to the 

 kilogramme. 



Dragon-fly (small), 

 Coccinella (Lady-bird), . 

 Dragon-fly (common), 

 Tipula, or Daddy-long-legs, . 



Drone (blue), 



Cockchafer, 



Lucanus ) Stag-beetle (female), 



cervus j Stag-beetle (male), 

 Rhinoceros-beetle, .... 



sq. 



yds. ft. in. 



11 8 92 

 7 2 56 

 5 13 87 

 5 2 89 

 3 5 11 

 1 2 741 

 1 3 541 

 1 2 20 

 1 2 50 

 1 1 391 

 8 33 

 6 122J 



Stork, 



Vulture, 



Crane of Australia, . 



sq. 



yds. ft. inch. 

 1 1 104* 

 5 1421 

 4 100J 

 2 113 

 2 20 

 1 116 

 139 



" It is easy, by the aid of this table, to follow the order, always decreasing, 

 of the surfaces, in proportion as the winged animal increases in size and weight. 

 Thus, in comparing the insects with one another, we find that the gnat, which 

 weighs 460 times less than the stag-beetle, has 14 times more of surface. 

 The lady-bird weighs 150 times less than the stag-beetle, and possesses 5 times 

 more of surface, &c. It is the same with the birds. The sparrow weighs about 

 10 times less than the pigeon, and has twice as much surface. The pigeon 

 weighs about 8 times less than the stork, and has twice as much surface. 

 The sparrow weighs 339 times less than the Australian crane, and possesses 

 7 times more surface, &c. If now we compare the insects and the birds, 

 the gradation will become even much more striking. The gnat, for example, 

 weighs 97,000 times less than the pigeon, and has 40 times more surface ; 

 it weighs three millions of times less than the crane of Australia, and possesses 

 140 times more of surface than this latter, the weight of which is about 9 kilo- 

 grammes 500 grammes (25 lbs. 5 oz. 9 dwt. troy, 20 lbs. 15 oz. 2£ dr. avoirdu- 

 pois. 



" The Australian crane is the heaviest bird that I have weighed. It is that 

 which has the smallest amount of surface, for, referred to the kilogramme, it does 

 not give us a surface of more than 899 square centimetres (139 square inches), 

 that is to say, about an eleventh part of a square metre. But every one 



* " On the Flight of Birds, of Bats, and of Insects, in reference to the subject of Aerial Locomo- 

 tion," by M. de Lucy, Paris. 



VOL. XXVI. PART II. 5 H 



