Insects. 



8009 



Moreover, so far from the larva? choosing damp or moist places, the reverse is the case, 

 as every pupa-digger knows. I am so satisfied now on these points that I rarely 

 trouble myself to examine the moss, or dig, except on those sides or iu dry places. 

 From these well-known facts I infer, nay conclude, that pupae in a state of nature do 

 not necessarily require moisture, or at any rate very little. I therefore do not damp 

 them, and am relieved from the difficulties which, more or less, stand in the way of- 

 those who do. I acknowledge that some dry up. The best way, in my judgment, to 

 obviate this aggravating result is to keep them in a cool room, and if there be a cur- 

 rent of air passing through the room so much the better. I may just add here, that 

 many pupae dry up through having been injured when dug up, or taken from bark, 

 moss, &c. The slightest touch, especially when recently turned, is sufficient to kill 

 them. In reference to Mr. Norton's second question, " Is the growth of the wings of 

 an insect fresh from the pupa affected by the temperature ?" I should say that there 

 can be no manner of doubt about it. It may be proved in the simplest way. Take 

 two perfect insects just emerged, say H. progemmaria. Leave one in a cold room, 

 and bring the other down and place it on the chimney-piece in a room where there is 

 a fire. 1 did this the other day. The one in the warm room expanded its wings in 

 a quarter of an hour, while that in the cold required five hours to complete the ope- 

 ration. — J. Greene ; Cubley Rectory, Doveridge, Derby. 



On the Plan upon which Bees and Wasps construct their Cells. 

 By Edwin Brown, Esq.* 



It has until lately been the universally received opinion that the 

 hive-bee makes hexagonal cells, owing to an instinctive preference 

 for that form above all others. Many profound calculations have 

 been made, by Lord Brougham and others, to prove that intelligence 

 or instinct has enabled the bee practically to solve the problem of the 

 exact angle which ensures the greatest amount of internal space, co- 

 existently with the smallest possible expenditure of wax. 



I am prepared to admit that it is the desire of the bee to produce a 

 commodious cell by an economical outlay of wax ; but that the intent 

 of the bee is instinctively to make a cell with exactly six sides, is an 

 hypothesis the truth of which I cannot concede. 



Bees, wasps, ichneumons, spiders and all other insects which con- 

 struct nests, cocoons or cells, whether of paper, wax or silk, attempt 

 in these structures to produce hollow cylinders having hemispherical 

 terminations ; and it is only, I believe, when a number of apartments 

 are placed side by side that the hexagonal shape is arrived at. It is 

 not difficult to see the reason for this. The hexagon is the only poly- 

 gonal form into which an area can be uniformly divided ; and it is 



* Read before a Meeting of the Midland Scientific Association, April 2. 

 VOL. XX. 2 B 



