ARCHITECTURE OF BIRDS. 261 



will spy his opportunity, and go off the richer for a thread or 

 two. 



Collections of nests are very recent, not numerous, and, as yet, 

 not rich. In that of Rouen, however, which is remarkable for its 

 arrangement ; in that of Paris, where many very curious specimens 

 may be examined ; you can distinguish already the different industries 

 which create this master-piece of the nest. What is the chronology, 

 the gradual growth of it ? Not from one art to another (not from 

 masonry to weaving, for example) ; but in each separate art, the birds 

 which abandon themselves to it are more or less successful, according 

 to the intelligence of the species, the abundance of material, or the 

 exigency of climate. 



Among the burrowing birds, the booby, and the penguin, whose 

 young, as soon as born, spring into the sea, content themselves with 

 hollowing out a rude hole. But the bee-eater, the sea-swallow, which 

 must educate their young, excavate under the ground a dwelling which 

 is admirably proportioned, and not without some geometrical design. 

 They furnish it, moreover, and strew it with soft yielding substances 

 on which the fledgling will be less sensitive to the hardness or freshness 

 of the humid soil. 



Among the building-birds, the flamingo, which raises a pyramid of 

 mud to isolate her eggs from the inundated earth, and, while standing 

 erect, hatches them under her long legs, is contented with a rude, 



