OF PAPILIONACEOUS INSECTS. 53 



There is considerable variation in the number of 

 eggs laid by different species. The Silk-worm Moth, 

 (Phalana mori,} lays five hundred ; the Great Goat 

 Moth, ( Cossus ligniperdaj) one thousand ; and the 

 Tiger Moth, ( Calimorpha cagd) one thousand six 

 hundred. This may be considered extraordinary 

 fecundity in such small animals ; but, compared to the 

 Queen Bee, it sinks into insignificance ; for she 

 extrudes the extraordinary number of 2,419,200 in 

 a lunar month, and exceeds in fruitfulness every 

 other animal in the world. 



Some of the larger fishes lay vast numbers of eggs ; 

 for Lewenhoek has ascertained that the sturgeon's 

 roe contains 1,500,000, and the codfish deposits the 

 amazing number of 9,000,000. 



The eggs of birds are all nearly of the same shape, 

 which is supposed to arise from the similarity of the 

 form of these animals. The eggs of insects, on the 

 contrary, are infinitely varied in their forms, and why 

 this should be the case, it is not easy to conjecture. 

 Dr Paley has justly remarked in his Natural Theology ', 

 that the cause of these differences of forms is, for the 

 most part, concealed from human investigation. 

 Besides the dissimilarity of shape, they have a character 

 which distinguishes them from all the eggs of other 

 oviparous animals, being for the most part exter- 

 nally ornamented with a variety of beautiful figures. 

 Some are figured on one side, and plain on the other ; 

 while the eggs of the Tusseh Silk-worm, (Attacus 

 pappea,} and some other of the Moths of the 

 division Bombyx, are always orbicular and depressed 



