222 Special Instincts. Chai\ viii. 



workmanship of the bee has been greatly exaggerated ; so much so, 

 that whatever the typical form of the cell may be, it is rarely, if 

 ever, realised. 



Hence we may safely conclude that, if we could slightly modify 

 the instincts already possessed by the Melipona, and in themselves 

 not very wonderful, this bee would make a structure as wonderfully 

 perfect as that of the hive-bee. We must suppose the Melipona to 

 have the power of forming her cells truly spherical, and of equal 

 sizes ; and this would not be very surprising, seeing that she already 

 does so to a certain extent, and seeing what perfectly cylindrical 

 burrows many insects make in wood, apparently by turning round 

 on a fixed point. We must suppose the Melipona to arrange her 

 cells in level layers, as she already does her cylindrical cells ; and 

 we must further suppose, and this is the greatest difficulty, that 

 she can somehow judge accurately at what distance to stand from 

 her fellow-labourers when several are making their spheres ; but 

 she is already so far enabled to judge of distance, that she always 

 describes her spheres so as to intersect to a certain extent ; and then 

 she unites the points of intersection by perfectly flat surfaces. By 

 such modifications of instincts which in themselves are not very 

 wonderful, — hardly more wonderful than those which guide a 

 bird to make its nest,— I believe that the hive-bee has acquired, 

 through natural selection, her inimitable architectural powers. 



But this theory can be tested by experiment. Following the 

 example of Mr. Tegetmeier, I separated two combs, and put between 

 them a long, thick, rectangular strip of wax : the bees instantly 

 began to excavate minute circular pits in it ; and as they deepened 

 these little pits, they made them wider and wider until they were 

 converted into shallow basins, appearing to the eye perfectly true or 

 parts of a sphere, and of about the diameter of a cell. It was most 

 interesting to observe that, wherever several bees had begun to 

 excavate these basins near together, they had begun their work at 

 such a distance from each other, that by the time the basins had 

 acquired the above-stated width (i. e. about the width of an ordinary 

 cell), and were in depth about one sixth of the diameter of the 

 sphere of which they formed a part, the rims of the basins intersected 

 or broke into each other. As soon as this occurred, the bees ceased 

 to excavate, and began to build up fiat walls of wax on the lines of 

 intersection between the basins, so that each hexagonal prism was 

 built upon the scalloped edge of a smooth basin, instead of on the 

 straight edges of a three-sided pyramid as in the case of ordinary 

 cells. 



I then put into the hive, instead of a thick, rectangular piece of 



