416 Rev. S. Haughton on the Form of the Cells. 



The British tree-wasp forms its pupa-cells in this manner, and, 

 in consequence of the pyramidal form of the hexagonal cells, 

 the comb opens out on the lower side, so as to present a larger 

 surface than on the upper side. 



2nd. Hexagonal cells formed of adjoining prismatic figures, 

 with rectilinear axes, terminated by a truncated plane, at right 

 angles to the axes of the prisms. 



These cells are found in wasps' nests from St. Lucia, in the 

 West Indies, and at Graham's Town, in South Africa, which 

 were placed at my disposal for this investigation by Mr. Robert 

 J. Montgomery. 



3rd. Hexagonal cells formed of adjoining prismatic figures, 

 with rectilinear axes, terminated by three faces of a rhombic 

 dodecahedron, which three faces also form each one-third of 

 the termination of a similar set of adjoining hexagonal prismatic 

 cells, placed end to end behind the first set of prisms. 



This double comb is produced by the well-known form of the 

 cells of the honey-bee. 



All these varieties of cells may be accounted for, simply by 

 the mechanical pressure of the insects against each other during 

 the formation of the cell. In consequence of the instinct that 

 compels them to work with reference to a plane, and of the 

 cylindrical form of the insects' bodies, the cells must be hexa- 

 gons ; and in consequence of the instinct that induces the bees 

 to form double combs, the mutual pressure of their heads 

 against each other compels the bottom of the cell to assume the 

 form of the rhombic dodecahedron. If we could imagine spherical 

 insects endowed with the instinct of working from a point and 

 not a plane, their cells would cease to affect the forms of the 

 hexagon and rhombic dodecahedron, and would imitate the 

 totally different form of the pentagonal dodecahedron — instances 

 of which may be seen in the bubbles produced in the froth of an 

 organic solution, and in the shapes of the elementary cells of 

 vegetables, equally restricted in their growth in every direction — ■ 

 and also in the pentagonal faces assumed by leaden bullets made 

 to fill completely the inside of a hollow shell, and then dis- 

 charged against a bank of earth, or a wall, from a mortar. 



On this subject, I cannot do better than quote the words of 

 Ruffon, who was the first person that put forward a rational 

 theory of the shape of the cells of bees. The passage which I 

 quote may be found in his * Histoire Naturelle,' tom. iv. p. 99 : — 



"Dirai-je encore un mot; ces cellules des abeilles, ces hexa- 

 gones, tant vantes, tant admires, me fournissent une preuve de 

 plus centre I'enthousiasme et I'admiration : cette figure, toute 

 geometrique et toute reguliere qu'elle nous paroit, et qu'elle est 

 en effet dans la speculation, n'est ici qu'un resultat mecanique 



