338 
BIRD-LIFE. 
content ourselves with a passing glance at these vast 
assemblies. 
In the interior of Germany we have but few birds 
which nest in companies : these consist of Rooks and 
different species of Swallows and Gulls. About large and 
ancient buildings in cities, and in the high and favour¬ 
ably-situated banks of rivers, we meet with the nests of 
the House and Sand Martins (Chelidon urbica and Cotyle 
riparia) in such numbers as to enable us, in a small way, 
to form some idea of these breeding colonies. The House 
Martin will build nest on nest four deep, under the 
gables, cornices, and other over-hanging portions of an 
edifice; while the Sand Martins excavate their holes in 
considerable numbers close to one another, enlarging the 
further end into the form of an oven. The numbers of 
these colonists rarely exceed a hundred pairs. Peace and 
good will are essential characteristics of these assem¬ 
blages of harmless little creatures; each individual pair 
lives quietly among the many, unenvious of the happiness 
of others; all quarrels and disputes cease as soon as 
the flock have finally assembled. Each family lives 
together, and yet the whole company may be said to 
form only one family. Such harmony as this cannot be 
witnessed without affording gratification to the spectator. 
The ancients, childish in their views of Nature’s work, saw 
miracles in these cases. Thus, Pliny relates the following 
marvellous story of the Sand Martin, which would raise 
that bird to the rank of an extraordinary benefactor 
of the human race:—“At the mouth of the Nile, near 
Heraclea, in Egypt,” says he, “the Swallows build nest 
upon nest, until they form a wall so strong as to present 
an insurmountable barrier to the inundations of the 
river; this dam is nearly a stadium in length, and could 
