i 5 4 THE POPULAR SCIENCE MONTHLY. 



intervals between these grains can receive, and set the water boiling, 

 all these cylinders will become six-sided columns." Buffon's com- 

 parison has been a good deal laughed at, yet it is not altogether bad. 

 He understood that each cell with its sides cut at regular angles was 

 not an individual work, nor the direct execution of the original plan ; 

 that it was a kind of resultant brought about by the forced neighbor- 

 hood, the mutual crowding and hindering of constructions conceived 

 on a simpler plan, and one more usual among insect^, the cylindrical 

 chamber. 



The humble-bees, which are hymenopterous insects, like honey- 

 bees, put their store of honey away in their old cocoons. When the 

 vessel is too small, they add to it at the opening a prolongation of wax. 

 It may even occur that they build single cells, of an irregular globular 

 form ; this is a first step, the primitive wax-working. There is noth- 

 ing very remarkable yet in this ; but the next step becomes more im- 

 portant. Between this rude simplicity and the work, so finished, of 

 the bee, we find something intermediate, the honey-cells of the domes- 

 tic melipone, of Mexico. The insect itself forms a transition, by its 

 external mai-ks, between the honey-bee and the humble-bee, and is 

 nearer to the latter. To preserve its honey, it builds a pile of large 

 spherical cells, all placed at equal distances apart, only that this dis- 

 tance is everywhere less than twice the radius of the spheres, so that 

 they all encroach on each other, and are kept apart by a perfectly flat 

 partition, having exactly the same thicknjess as the curved wall that 

 bounds the free and spherical portion of each cell. If three are found 

 to adjoin, the lines of separation cross at equal angles, and their com- 

 mon meeting-point rests on the top of a pyramid with three walls 

 formed by the three cells, exactly as in a honeycomb. Reflecting on 

 all this, Darwin says the thought occurred to him that, if the melipone, 

 which already builds its spheres at equal distances apart, were to come 

 to disposing them symmetrically and back to back upon two opj>osite 

 sides, there would result from this fact a construction as admirable as 

 the bottom of a double rank of cells in the hive. 



Has the constructive genius of the wasp and the bee passed through 

 theee transitions ? It is impossible to assert it ; but the evidence 

 shows, and calculation confirms it, that some modifications, slight 

 enough definitely, occurring in the instincts of the melipone, might 

 lead it, after an indefinite number of ages we must always calculate 

 on such periods of time to build those three-angled pyramids which 

 are already found in its constructions, in two or three ranks ; then to 

 build upon those pyramids, on each side, prolongations cylindrical in 

 principle, like those which the humble-bee puts on its cocoons, and 

 prism-shaped from their nearness to each other. Besides, such a con- 

 struction upon a flat surface of its honey-cells by the melipone would 

 be nothing very extraordinary ; in this way it builds the little cham- 

 bers where it deposits its grubs. 



