proper care to convert them into queens, and at once begin to enlarge the cells in which they are lodged. Their mode of proceeding is curious. In order to make it most intelligible, I will describe the work upon a single cell, which will apply to all those that contain worms intended for queens. After having selected a worker worm, they sacrifice three of the contiguous cells; taking away the worms and the pap and build around this one a cylindrical enclosure; its cell thus becomes a perfect tube, with rhomboidal base, for they do not tamper with the pieces of this base; if they damaged it they would uncover the three corresponding cells on the opposite side of the comb, and therefore would sacrifice the worms that inhabit them, which is unnecessary and which nature has not permitted. They therefore leave the rhomboidal base and are content with raising a cylindrical tube around the worm, which is thus placed horizontally, like the other cells of the comb. But this habitation is adapted to the intended royal worm for only the three first days of its existence; it requires a different situation for the other two days, during which it will still remain a worm. During these two days, which constitute so small a portion of the duration of its existence, it must live in a cell of nearly pyramidal form, the base of which is at the top and the point at the bottom. It seems that the workers are aware of this, for after the worm has completed its third day, they prepare the place to be occupied by its new lodging, gnawing away some of the cells located below the cylindrical tube, they mercellessly sacrifice the worms that are in them, and use the wax which they have just gnawed away to construct a new pyramidal tube which they solder at right angles to the first, working it downwards. The diameter of this pyramid decreases insensibly from its base, which is wide, down to the point. During the two days that the worm inhabits it, there is constantly a bee with her head more or less inserted in the cell: when a worker leaves it, another takes her place. They lengthen the cell as fast as the worm grows, they bring food, which they place before its mouth and around its body in a sort of band around it. The worm, which can only move in a spiral direction, turns incessantly to take the food before its head: it insensibly descends and at length arrives near the mouth of the cell: it is at this time that it must transform into a nymph. The care of the bees is no longer necessary: they close its cradle with an appropriate substance, and in proper time it undergoes its two metamorphoses. Schirach holds that bees never select other than _3 days old worms_, to give them the "royal education": I have ascertained, on the contrary, that this operation succeeds as well on worms aged only _2 days_. Permit me to relate at full length the evidence which I have acquired of this: it will demonstrate, at the same time, both the reality of the conversion of worker worms into queens, and the little influence which their age has upon the success of the operation. In a hive deprived of its queen, I caused to be placed some pieces of combs containing worker eggs and already hatched worms of the same kind. The same day, the bees enlarged several of the worm cells, and changed them to royal cells, giving to the worms in them a thick bed of jelly. We then removed 5 of the worms placed in those cells, and Burnens substituted for them 5 worker worms which we had witnessed hatching from the egg 48 hours previously. Our bees did not appear aware of this exchange: they fed the new worms as well as those selected by themselves; they continued enlarging the cells in which they were placed, and closed them at the usual time; they then incubated these 5 cells during 7 days, at the end of which time we took them away to preserve alive the queens which would be produced from them. Two of these queens emerged almost at the same moment, they were of large size and well formed in every respect. The three other cells having passed the term without any queen emerging, we opened them to ascertain their condition; we found a dead queen in nymph state in one of them, the other two were empty, the worms in them had spun their silk cocoons but had died before getting to the nymph state, and showed only a dried up skin. I can conceive nothing more conclusive than this experiment: it demonstrates that bees have the power of converting the worms of workers into queens, since they succeeded in procuring them by operating on the worms of workers which we ourselves had selected: it is equally demonstrated that, for the success of the process, it is not necessary that the worms be three days old, since those which we entrusted to the bees were only two days old.