When a laying queen is removed from a colony during the working season, eggs and larvæ of all ages are left behind. As indicated in Chapter II, any egg which has been fertilized may be made to develop into a queen. So also larva? from such eggs may, up to the third day, be taken to rear from without danger of producing inferior queens. Cells in which to produce queens will be started over some of these larvæ on the edges of the combs, or, by tearing down partitions and thus enlarging the lower portion of the cell, a beginning is obtained for a queen cell. Fig. 63 shows such queen cells constructed over eggs or larvæ originally designed to produce workers. They are known as emergency cells. The young larva is at once liberally supplied with a secretion, which is probably a production of the glands of the head, and which analyses have shown to be rich in nitrogen and fatty elements, being similar to that given at first to the worker larva. This is continued throughout the whole feeding period, while, as Dr. Von Planta has shown, in the case of the workers and drones, after the third day the proportion of the constituents of the larval food is so changed that they receive much less albumen and fat and more sugar. It is chiefly the influence of this food which causes the larva that would have developed as a worker to become a queen. The latter has somewhat changed instincts,, and its reproductive system is developed, instead of abortive as in the case of the worker. The size of the cell, and, to a less extent perhaps, its position, no doubt influence this development, but the food seems to be the main factor, for small cells built horizontally, if their larvæ are supplied with the food designed for royal larvæ, will be found to contain queens, and frequently these queens, even though small, are quite prolific, and show in all respects the instincts of a queen. [Illustration: Fig. 63.--Queen cells and worker brood in various stages. (Original.)] It is believed by most queen raisers that in order to secure the best development of the young queens a colony should be allowed to build but a few cells at a time. That their belief is not well founded is shown by the facts just cited concerning the large numbers of well-developed queen cells which produce also perfect and prolific queens. It lies within the skill of the bee-master to establish conditions favoring the production of food for the queen larvæ--the so called "royal jelly"--and this having been brought about, there need be no hesitancy in permitting the construction of hundreds of queen cells in one colony if such numbers are needed.