按键盘上方向键 ← 或 → 可快速上下翻页，按键盘上的 Enter 键可回到本书目录页，按键盘上方向键 ↑ 可回到本页顶部！
————未阅读完？加入书签已便下次继续阅读！
and at the same distance from the centres of the adjoining spheres in the other and parallel layer； then； if planes of intersection between the several spheres in both layers be formed； there will result a double layer of hexagonal prisms united together by pyramidal bases formed of three rhombs； and the rhombs and the sides of the hexagonal prisms will have every angle identically the same with the best measurements which have been made of the cells of the hive…bee。
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 make 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 in wood many insects can make； 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 largely； and then she unites the points of intersection by perfectly flat surfaces。 We have further to suppose； but this is no difficulty； that after hexagonal prisms have been formed by the intersection of adjoining spheres in the same layer； she can prolong the hexagon to any length requisite to hold the stock of honey； in the same way as the rude humble…bee adds cylinders of wax to the circular mouths of her old cocoons。 By such modifications of instincts in themselves 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； square 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 me 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 flat walls of wax on the lines of intersection between the basins； so that each hexagonal prism was built upon the festooned 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； square piece of wax； a thin and narrow； knife…edged ridge； coloured with vermilion。 The bees instantly began on both sides to excavate little basins near to each other； in the same way as before； but the ridge of wax was so thin； that the bottoms of the basins； if they had been excavated to the same depth as in the former experiment； would have broken into each other from the opposite sides。 The bees； however； did not suffer this to happen； and they stopped their excavations in due time； so that the basins； as soon as they had been a little deepened； came to have flat bottoms； and these flat bottoms； formed by thin little plates of the vermilion wax having been left ungnawed； were situated； as far as the eye could judge； exactly along the planes of imaginary intersection between the basins on the opposite sides of the ridge of wax。 In parts； only little bits； in other parts； large portions of a rhombic plate had been left between the opposed basins； but the work； from the unnatural state of things； had not been neatly performed。 The bees must have worked at very nearly the same rate on the opposite side of the ridge of vermilion wax； as they circularly gnawed away and deepened the basins on both sides； in order to have succeeded in thus leaving flat plates between the basins； by stopping work along the intermediate planes or planes of intersection。
Considering how flexible thin wax is； I do not see that there is any difficulty in the bees； whilst at work on the two sides of a strip of wax； perceiving when they have gnawed the wax away to the proper thinness； and then stopping their work。 In ordinary combs it has appeared to me that the bees do not always succeed in working at exactly the same rate from the opposite sides； for I have noticed half…completed rhombs at the base of a just…commenced cell； which were slightly concave on one side； where I suppose that the bees had excavated too quickly； and convex on the opposed side； where the bees had worked less quickly。 In one well…marked instance； I put the comb back into the hive and allowed the bees to go on working for a short time and again examined the cell； and I found that the rhombic plate had been completed； and had become perfectly flat： it was absolutely impossible； from the extreme thinness of the little rhombic plate； that they could have affected this by gnawing away the convex side； and I suspect that the bees in such cases stand in the opposed cells and push and bend the ductile and warm wax （which as I have tried is easily done） into its proper intermediate plane； and thus flatten it。
From the experiment of the ridge of vermilion wax； we can clearly see that if the bees were to build for themselves a thin wall of wax； they could make their cells of the proper shape； by standing at the proper distance from each other； by excavating at the same rate； and by endeavouring to make equal spherical hollows； but never allowing the spheres to break into each other。 Now bees； as may be clearly seen by examining the edge of a growing comb； do make a rough； circumferential wall or rim all round the comb； and they gnaw into this from the opposite sides； always working circularly as they deepen each cell。 They do not make the whole three…sided pyramidal base of any one cell at the same time； but only the one rhombic plate which stands on the extreme growing margin； or the two plates； as the case may be； and they never complete the upper edges of the rhombic plates； until the hexagonal walls are commenced。 Some of these statements differ from those made by the justly celebrated elder Huber； but I am convinced of their accuracy； and if I had space； I could show that they are conformable with my theory。
Huber's statement that the very first cell is excavated out of a little parallel…sided wall of wax； is not； as far as I have seen； strictly correct； the first commencement having always been a litt