If robbing has begun it may sometimes be stopped by throwing coarse grass or weeds over the entrance of the hive attacked, or by leaning a pane of glass against its front, the entrance being, of course, contracted as indicated above. These plans tend to confuse the robbers for a time, and meanwhile the rightful occupants of the hive may be able to organize for defense. If convenient the colony attacked may be moved a distance of a half mile or more and placed as far as possible from other apiaries until it can recuperate. Another plan in extreme cases is to put the colony in a dark cellar for a few days, confining the bees to the hive with wire cloth, so as to allow plenty of ventilation, as described under the head of "Moving bees." When brought out of the cellar it is well to place the colony on a new stand, apart from the other bees, contract the entrance, and lean a board against the front of the hive. It is also safest to bring it out late in the day, even just at dusk, so the bees will begin flying from it gradually and not attract the attention of robbers. It may be well, when removing a colony from its stand to save it from robbers, to put in its place a hive with combs containing a little honey and pollen. The robbers, instead of scattering and entering adjacent hives, will continue to visit the same stand, their numbers gradually diminishing as the honey gives out and the pollen is sucked dry. If meanwhile the entrances of adjoining hives have been contracted and these colonies are fairly strong and in normal condition, individual robbers will be successively repulsed as they appear. Quiet will thus be eventually restored. LAYING WORKERS. Although laying workers are not strictly enemies of their kind, their work hastens the extinction of the colony to which they belong, in case the latter has become queenless and is without the means of rearing another queen. They cause the expenditure of the stores and strength of the colonies in a vain though well-meant endeavor to perpetuate their species; the eggs which laying workers deposit, and for whose development through the larval stage much honey and pollen are required, only resulting in the production of a lot of drones, for the most part weak and dwarfed. If not discovered until the hive is nearly depopulated, the remaining old bees should be brushed off, and the combs, after the sealed drone brood has been unmapped and jarred out, may be distributed among other colonies. Should the affected colony still be worth saving, combs containing emerging bees should be added and a queen introduced a few days later, or a queen cell inserted, as soon as the added brood has stocked the hive well with young bees. =BOOKS AND JOURNALS RELATING TO APICULTURE.= The following are among the leading books and journals relating to apiculture: BOOKS.