ILLUSTRATIVE NOTES. 335 



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 symmetiy, especially in the case 

 of the ant, whose life is complicated with so many incidents, so many 

 unforeseen exigencies, that she would 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 Compiegne, 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 (mergulct), 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. 



