To convert this hypothesis into a demonstration, Von Berlepsch invited to his apiary in succession the two great comparative anatomists Professors Leuckart and Von Siebold, and furnished each with a number of both drone and worker eggs for microscopic examination. Leuckart examined the surfaces of the eggs; Von Siebold, who followed him, tried the interiors, and the latter by this means was triumphantly successful, for, after the most careful preparation of his subjects, he detected in thirty out of forty worker eggs from one to four spermatozoa apiece, while in his twenty-four drone eggs he found not a single one. The exceptions were insufficient to invalidate the results, for the ten worker eggs in which no signs of impregnation were found were only the failures of observation to be naturally expected in so delicate a scrutiny. Thus the fact was established that eggs which produce male bees are descended from the female only—in other words, that drones have no fathers!
Most strikingly has this law been corroborated by a discovery which we owe to the introduction of the Italian bee—a discovery, too, which any bee-keeper can make for himself. If an Italian queen is crossed with an English drone, or vice versa, the workers only of her progeny will be mongrels—the drones will invariably retain the pure blood of the queen, thus proving to demonstration that they owe their origin to her alone. Should a mongrel drone be then observed, it will be a sure sign that a fertile worker is in the hive: the queen will not be its mother. Dr. Dönhoff, we are told, confirmed the same law by a converse method, having in 1855 obtained a worker bee from a drone egg which he had artificially impregnated with the male fluid.
The queen, as we have observed, is capable before fertilisation of becoming the mother of drones, but it is believed by some that if she has once commenced drone-laying it is impossible for her to become subsequently fertilised. Mr. Langstroth, however, mentions an instance to the contrary, where a queen of his, after persistently laying drone eggs for a week or two, became after that the happy mother of a thriving colony of workers. Von Berlepsch alludes to this case (with others like it), but is unconvinced, being suspicious that here again it was a fertile worker and not the queen who laid the drone eggs. But looking to the fact that many permanently unfertile queens lay drone eggs, while others lay no eggs at all, does it not seem reasonable that a similar difference may subsist previous to fecundation? Thus, while the Baron is on firm ground as to the general rule, we incline to a belief that as to the exception the American observer is quite correct.
Dzierzon thus writes: "In general, so long as the young queen continues her wedding flights—which in the warm summer she does at the very most for four weeks, but in the cool spring or autumn, when life and development are slower in the hive, she still pursues for even five or six weeks—she is capable of becoming properly fertile." But some queens continue to fly long after it is hopeless, cases being recorded in which they have gone on for ten or twelve weeks. The same observer speaks of having had several young queens which were either lame in their wings or born in a continued cold season, so that they were prevented from leaving the hive, and thus developed into confirmed drone-breeders. The queen leaves the hive every fine day till her purpose is accomplished, and this led Bevan and others to surmise that she met successively with several drones till one Of them lost his life in consequence; but we do not find in later authorities any confirmation nor even mention of this conjecture, and it may be set down as entirely improbable. In the case observed by Von Klipstein, and referred to above ([page 22]), as the queen met with her death shortly after, he sent her to Leuckart, who found that from this obviously first impregnation her organs were so completely filled as to imply no need for a second. Leuckart has elsewhere stated that a queen's spermatheca is capable of containing twenty-five millions of spermatozoa, so that there need be no wonder at the fact of a single fecundation being sufficient to answer for her entire term of existence.
The fertile workers, which by their course of adding to the drone stock may prove a terrible nuisance in a hive, were ascertained by Huber to be always hatched in close proximity to the queen cells, whence he conjectured that they obtained by accident a portion of the royal jelly designed for the rearing of princesses. Von Berlepsch and Langstroth prefer the theory that such jelly was purposely given them, and the conversion of their own cells into royal ones commenced, but that the intention was afterwards abandoned, as it is known that bees often, start more of such cells than they ultimately proceed with. They are of only exceptional occurrence in hives in a normal condition, but in a queenless stock they very often appear, sometimes even in considerable numbers, having been probably fostered with the jelly, but at too late a period to convert them into queens. They usually deposit their eggs correctly in drone cells, though drone-breeding queens lay in those of workers and even in royal cells—thus evincing a presence of the will though an absence of the power. To get rid of a fertile worker it has been recommended by Mr. Rorl to "drive" the bees ([Chap. V. § iv.]) to an empty hive, and place this in a near spot; all will return to their old home except the one to be got rid of, she having probably never flown before, and therefore not knowing her way.
§ X. RELATION OF SEX TO CELLS.
There remains the very interesting question of the connection between sex and cells, which, if it be not paradoxical to say so, is as a general rule invariable; that is to say, when both the queen and the hive are in a normal condition, the eggs laid in each class of cells produce respectively workers and drones without failure or exception. But in abnormal circumstances, as with a drone-breeding queen, the law does not hold, and drones of a diminished size are hatched from worker cells, though the bees, on discovering the state of things, do their best by subsequent elongation to adapt the cradles to their unexpected occupants. Such is the explanation of the existence of "small drones;" but workers hatched in drone cells do not appear to be in any way peculiar. In regard then to the main fact we are confronted with the question, Has the queen a knowledge, at the moment of laying, of the gender of each particular egg? Rather, it would seem, she has the power of making it what gender she pleases by compressing her spermatheca or not at the instant of its passing down her oviduct. We must however refer to an ingenious theory to the contrary, quoted by Langstroth as started by his friend the late Mr. Wagner of Philadelphia, and which has been approved by many in this country and Germany also. It is to the effect that not the queen's own will, but the narrow limits of the worker cells, administer the above compression, while the more spacious drone cells allow her body to be inserted without such effect. Von Berlepsch however, it is safe to say, has absolutely demolished this mechanical explanation; and as some recent writers have quoted the "Wagner theory" with approval, it may be best to give the German observer's principal objections in his own words:—
"This explanation is thoroughly untenable; for—(a) perfectly new worker cells are fully as wide as very old drone cells in which breeding has taken place many times, and yet, as found by experience, female bees come from the former and males from the latter, (b) Many queens are of a strikingly slender form, some of them occasionally so small that they can scarcely be distinguished from workers, and yet they have no proclivity to drone-laying—which must however have been the case if the narrow cell effected the fertilisation of the egg by pressure.... (c) A queen lays even in cells that are scarcely begun, with which, therefore, the proportion of the diameter to the thickness of her body can exercise no influence at all, and yet drones come forth from the drone cells and workers from the worker cells. (d) If there are no drone cells at her command, and the stock is in want of drones, the queen lays male eggs in worker cells, and drones hatch from them.... (i) A fertile queen, if introduced with her colony into a hive containing nothing but drone comb, would naturally [on such hypothesis] furnish the drone cells with eggs as she would worker cells, and make no difficulty about it. But she does make a very great difficulty—for a long time she lays no eggs in the cells at all, but lets them drop, or tries to escape abroad with her entire colony. But at last she does lay in the drone cells, and what ensues? Ordinary worker bees come forth." Instances follow of experiments decisively proving this. It is only fair, however, to add that Mr. Wagner's theory does not necessarily degrade the monarch of the hive into "a mere egg-laying machine," as Von Berlepsch regards it in some of his arguments, for she might still exhibit intelligence in deciding which cells to lay in, even if the determination of the sex of the egg rested finally with the cell which she had chosen.
The queen then exercises a personal control over each egg as she deposits it, but, unless interfered with by irregular circumstances, she adapts her will to the cells and chooses the cells according to the requirements of the hive. But when both drones and workers are in requisition she lays her eggs in each class of cells just as she comes to them, as to which fact the Baron gives abundant evidence, having in one instance observed a queen make no fewer than five changes in a day from worker to drone cells or vice versa without any intermission. Inconsistent as it may appear, she also herself deposits in royal cells the eggs which are to hatch into her rivals—that is, when these cells have been prepared with a view to swarming;—for the preponderance of argument goes against the belief that eggs are ever removed into these by the workers.[13] In addition to determining the sex she is further capable of regulating to a large extent the total number of eggs she lays, and thus of modifying the growth of the population with the character of the season and the condition of the colony; thus a queen that has been transferred from a weak to a strong hive has been know to vary in two or three days from no eggs at all to two thousand a day. She lays during some ten months of the year, suspending the process in November and December. For her first season she lays almost exclusively worker eggs.
[13] The eggs when once deposited adhere to the cells and could not be removed without ruining them; but occasionally when fresh laid they stick to the body of the queen, or even of a worker. Queenless stocks sometimes in their temporary insanity start new queen cells without thinking where the eggs are to come from; but these will remain empty unless some fertile worker' tries her skill.