ILLUSTRATIVE NOTES, 835 
—so much so, that occasionally between these things, at first sight so 
nearly alike, a whole world will intervene, without the power of 
bringing them together. 
It has been asserted and repeated that the works of insects pre- 
sented an absolute similarity, a mechanical regularity. And yet our 
Reaumurs and our Hubers have discovered numerous facts which 
positively contradict this pretended symmetry, especially in the case 
of the ant, whose life is complicated with so many incidents, so many 
unforeseen exigencies, that she wculd never provide against them but 
for the rapid discernment, the promptitude of mind, which is one of 
the most striking characteristics of her individuality. 
It has been supposed that the nests of birds are always con- 
structed on identical principles. Not at all. A close observation 
reveals the fact that they differ according to the climate and the 
weather. At New York, the baltimore makes a closely fitted nest, 
to shelter him from the cold. At New Orleans his nest is left with 
a free passage for the air to diminish the heat. The Canadian 
partridges, which in winter cover themselves with a kind of small 
pent-roof at Compiégne, under a milder sky do away with this pro- 
tection, because they judge it to be useless. The same discernment 
prevails in relation to the seasons. The American spring, in the open- 
ing years of the present century, occurring very late, the woodpecker 
(of Wilson) wisely made his nest two weeks later. I will venture to 
add that I have seen, in southern France, this delicate appreciation 
of climatic changes varying from year to year; by an inexplicable 
foresight, when the summer was likely to be cold, the nests were 
always more thickly woven. 
The guillemot of the north (mergula), which fears above all things 
the fox, on account of his partiality for her eggs, builds her nest on 
a rock level with the water, so that, no sooner are they hatched than 
the brood, however closely dogged by the plunderer, have time to 
escape in the waves. On the other hand, here, on our coasts, where 
her only enemy is man, she makes her nest on the loftiest and most 
precipitous cliffs, where man can with difficulty reach it. 
Se 
