498 HABITATIONS OF INSECTS. 



times also they have occasion to shorten the cells. When 

 they wish to lengthen an old comb, the tubes of which 

 have acquired their full dimensions, they gradually di- 

 minish the thickness of its edges, gnawing down the sides 

 of the cells till it assumes the lenticular form : they then 

 engraft a mass of wax round it, and so proceed with 

 new cells. 



Variations, as has been already hinted, sometimes take 

 place in the position and even form of the combs. Oc- 

 casionally the bees construct cells of the common shape 

 upon the wood to which the combs are fixed, without 

 pyramidal bottoms, and from them continue their work 

 as usual. These cells with a flat bottom, or rather with 

 the wood for their bottom, are more irregular than the 

 common ones; some of their orifices are not angular, and 

 their dimensions are not exact, but all are more or less 

 hexagonal. Once when disturbed, Huber observed 

 them to begin their combs on one of the vertical sides 

 of the hive instead of on the roof. When particular 

 circumstances caused it, as, for instance, when glass was 

 introduced, to which they do not like to fix their combs, 

 he remarked that they constantly varied their direction ; 

 and by repeating the attempt, he forced them to form 

 their combs in the most fantastic manner. Yet glass is 

 an artificial substance, against which instinct merely 

 cannot have provided them : there is nothing in hollow 

 trees, their natural habitation, resembling it. — W T hen 

 they change the direction of their combs, they enlarge 

 the cells of one side to two or three times the dia- 

 meter of those of the other, which gives the requisite 

 curve. 



