THE EAGLE, . 
401 
merable glutinous threads, which have been drawn irregularly 
across each other, and have hardened by exposure to the air 
into a material which much resembles isinglass. The natives 
say that the construction of a single nest occupies a pair 
of birds for two full months ; so that there is some proba- 
bility that the material may really be secreted by the birds 
themselves. 
The nests are only used for one purpose. They are steeped 
in hot water for a considerable time, when they soften into a 
gelatinous mass, which forms the basis of a fashionable soup, 
and is not unlike the green fat of the ordinary turtle. Indeed, 
those who have partaken of birds’-nest soup say, that if it were 
seasoned in a similar manner, it might easily be taken for turtle 
soup. The Chinese value this soup highly, thinking that it 
possesses great, power of restoring lost strength. It is, how- 
ever, far too costly to be obtained by any but the rich, the best 
quality fetching rather more than sixty shillings per pound. 
There are at least four species of swallow that make these 
curious nests, and the natives say that the entrance to the caves 
is always occupied by another kind of swallow, which makes a 
nest of mixed moss and gelatine, and which fights the valuable 
birds and drives them away. They therefore always attack 
the intruders, and endeavour to knock down their nests with 
stones. The nests are very small and shallow, and seem 
scarcely capable of accommodating either eggs or young birds. 
My own specimen is exactly two inches in length, one inch and 
three-quarters in breadth at its widest point, and scarcely more 
than half-an-inch deep. Its internal shape is exactly that of a 
spoon-bowl, one-third of which has been cut off abruptly near 
the handle. 
None of the purely predacious birds are remarkable for their 
skill in architecture, and the Eagle ( ’ A quila chrysaetos) is no ex- 
ception to the general rule. The nest of this magnificent bird 
is nothing more than a huge mass of sticks flung at random on 
some rocky ledge, and having a shallow depression in which the 
young can lie. In general shape, or rather in shapelessness, it 
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