OF ARTS AND SCIENCES : JANUARY 9, 1866. 73 



Of all the parts of the cell there is none where the variation is more 

 striking than in the rhombic faces of the base. This fact is the more 

 noteworthy, since it is upon these, and the angles they make with each 

 other and the sides, that rests the nicest part of the problem relating to 

 the adaptation of the cell to the contained bee. The relative size of the 

 faces may be so changed that two of them make nearly the whole of 

 the base, while the third almost vanishes, or one of the faces may have 

 any size between this extreme and the normal one. 



The fourth face, which has been so often noticed, has generally been 

 spoken of as belonging more especially to those cells which are inter- 

 mediate between the cells of drones and workers. Although it occurs 

 in these, we have found it quite common in the middle of pieces of 

 comb consisting solely of either worker, drone, or honey cells.* In 

 one piece of worker comb containing about five hundred cells, nearly 

 all had a fourth face. 



The causes which lead to the introduction of the fourth face are 

 chiefly two, irregularity in the size of the cells and incorrect align- 

 ment of them on the two sides of the comb. Each cell on one side of 

 the comb being normally in contact, by its rhombic faces, with three 

 cells on the other, and these fitting exactly, if a cell is increased, it will 

 project beyond them, and thus come in contact with a fourth, and a new 

 face will be formed. We have seen this happen in a single cell, but 

 very commonly a row of cells increases for four or five cells, and grad- 

 ually diminishes again to the ordinary size. With this increase and 

 decrease of the cell, the fourth face comes and goes. 



Incorrect alignment is the more common cause.f If a given row of 



* These were studied either after cutting away the body of the cells, leaving only 

 the basal plate which separates those of opposite sides, or by means of casts ob- 

 tained by filling the cells with plaster of Paris. After this last has dried, if the 

 mass is heated, the wax is absorbed by the plaster, when the casts of the two sets 

 of cells separate. In old brood-combs, where many successive cocoons have been 

 spun, these form a thick and resisting cast of the base of the cell and may be ex- 

 tracted, giving its precise form. In some instances, fourteen distinct layers of co- 

 coons were counted, showing the number of broods which had occupied the cells. 



t This introduction of the fourth face to the basal pyramid, through incorrect 

 alignment, was thoroughly investigated several years since by Mr. Chauncey Wright, 

 of the Nautical Almanac Office, and who, at the same time, constructed models il- 

 lustrating his views. These models are deposited in the Museum of Comparative 

 Anatomy and Physiology at Cambridge. For a discussion of various points con- 

 nected with the geometry of the cell, see his article, entitled The Economy and 

 Symmetry of the Honey-Bee's Cell, in the Mathematical Monthly for June, 1860. 

 VOL. VII. 10 



