RANGE OF NURSERIES 



each curves over all those which lie below it, down to the 

 ground floor, which communicates with the subterranean 

 lodges. They are not always, however, arranged with the 

 same regularity, for ants do not follow an invariable plan ; it 

 appears, on the contrary, that nature has allowed them a 

 certain amount of freedom in this matter, and that they can 

 vary their method at will according to circumstances. But 

 however fantastical their habitations may appear, we always 

 observe that they have been built in concentric stories. 



On examining each story separately, we see a number of 

 carefully formed cavities or halls, lodges of narrower dimen- 

 sions, and long galleries which serve for general communica- 

 tion. The arched ceilings covering the most spacious places 

 are supported either by little columns, slender walls, or 

 regular buttresses. We further notice chambers that have 

 but one entrance, communicating with the lower story, and 

 large open spaces serving as a kind of crossing or junction in 

 which all streets terminate. 



Such is the general plan on which the habitations of these 

 ants are constructed. Upon opening them we discover the 

 apartments, as well as the large open spaces, filled with 

 adult ants; but we always find their pupae collected in 

 chambers which are nearer to or further away from the 

 surface according to the time of the day and to the tempera- 

 ture ; in this respect ants are endowed with great sensibility 

 and appear to know what degree of heat is best suited to 

 their young. 



The ant-hill contains sometimes more than twenty stories 

 in its upper portion, and at least as many under the surface 

 of the ground, an arrangement which must enable the ants 

 to regulate the heat to a nicety and with the greatest ease. 

 When a too-burning sun makes the upper apartments over- 

 warm, the insects withdraw with their little ones to the 



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