Darwin's example what infinitely harder things must be accepted by those who decline to accept this. Mr. Darwin, like every really truth-loving controversialist, far from desiring to shroud, invites special attention to any seeming weaknesses in his position; and, therefore, when contending that all the faculties commonly classed as instincts, are exclusively due to natural selection, of course takes care to particularise the cellmaking faculty of the hive bee. And here, again, I gladly bear my humble testimony to the partial success he has achieved. Although bound to protest against the claim set up by him, on behalf of natural selection, to the entire credit of producing the hive bee's most remarkable characteristic, I cannot but think he has succeeded in removing all the apparent difficulties of believing that natural selection's share may have been not less important in that than in any other productive operation in which it takes part. In popular estimation the hive bee is a heaven-born mathematician which, having been set the problem how to fill a given space with waxen cells with the least loss of room and expenditure of material, arrives by intuition and instantaneously at a solution which Newton himself was ignorant of, and to which, but for his discovery of the fluxional calculus, it would have been impossible for his follower, Maclaurin, to attain. And, doubtless, it may excusably be deemed supernatural that the insect should adopt off-hand precisely that six-sided figure, and precisely that inclination of the angles of the same figure's pyramidal roof or floor, which, only by very refined and recondite investigation, can be scientifically shown to be those best fitted for the purpose. Mr. Darwin has, however, adduced strong grounds for supposing the amazing architectural skill thus displayed to have been acquired, not suddenly, but by the same slow degrees as those which are so clearly traceable throughout organic progress in general. At the lower end of a short apiary series, he observed humble bees using their old cocoons for honey pots, sometimes adding to them short tubes of wax, and likewise making separate and very irregular cells entirely of wax. At the higher end of the series, he saw hive bees making double layers of cells, each cell an hexagonal prism with the basal ends of its six sides bevelled so as to fit on to a pyramid formed of three rhombs, and each of the three rhombs which compose the pyramidal base of a single cell on one side of the comb entering into the composition of one of the three adjoining cells on the opposite side. Intermediately, he found the Mexican _meliponae domesticae_ depositing their honey in cells nearly spherical, and of nearly equal sizes. 'These cells, although aggregated into a mass otherwise irregular, are always at such a degree of nearness to each other that they would have intersected or broken into each other if the spheres had been completed. But this is never permitted, the bees