Hives found to be queenless may be supplied either with matured queens or with queen cells. If the latter are sufficiently numerous, their introduction may easily be effected by exchanging a comb in each hive; if they have to be cut out and placed loosely in the new hive, a triangular piece of comb should then be removed with them, to be used as a block in preventing any pressure coming on them. A space must be cut out of the middle in the centre combs of the hive into which they are to be introduced. They must not be so loose as to be in danger of falling out, but if such seems likely a little melted wax should be applied with a feather. Special care must be exercised not to bruise the royal embryos, as a very slight pressure is likely to be fatal. It is important not to perform the operation till they are within three or four days of coming forth, which may be known to be the case from the brown look of the tops of the cells, the wax having been removed. It is always easier to introduce royal brood into queenless hives than matured queens, because bees are reluctant to receive stranger queens, whilst they will tolerate one hatched in the hive, who will speedily depart to seek a drone. Bee-masters mostly use small hives for queen-rearing, as explained in the section on "Nucleus Hives" (page 197). It is not however indispensable to use other than the ordinary hives, and Mr. Langstroth gives the following as the very best mode of procedure. Place an empty hive on the top of a well-filled one, giving communication through crown and floor boards and turning their entrances opposite ways (one of his plans, by the bye, for procuring an artificial swarm). The young bees will many of them take to the upper hive--if not they must be enticed into it by food--and when there are sufficient of them, a brood comb with adhering bees must be inserted and the connection closed. After a few days this nucleus hive may be removed, a few steps at a time, and another, if desired, take its place and be raised in the same way. Queen-rearing operations must be confined to warm weather and when drones are abundant. Royal cells are often built so close together that it is difficult to remove one without injuring another. As a remedy for this Dr. Dzierzon has made the important discovery that any convenient worker cell may be made to produce a queen by the removal to it of some of the royal jelly from an unsealed cell; by placing this on the inner margin of the cell selected, the bees will adopt and rear the larva as desired. § VIII. INTRODUCING NEW QUEENS. This is an operation that is continually being practised for the purpose of Italianising a colony, though there are other occasions for its adoption, as on the loss or the superannuation of the old queen. We will in the first place describe the mode of procedure with a frame hive.