BEE-spoke-data/bees-v0 huggingface dataset:
The phenomenon of dominance, remarkable as it is, is not the essential part of Mendel's discovery, indeed, it is not present in every case, the first generation of the hybrids being sometimes intermediate in character. We must bear in mind that an individual animal or plant is the product of the union of two germ cells, or _gametes_, as they are called, the one derived from the male parent, and the other from the female parent. Thus an individual is of double origin.
Now the essential part of Mendel's discovery, recognised by the disoverer himself, is that the gametes are pure in respect of either of the characters in each of the pairs of alternative characters we have been considering ; in other words, that a gamete can carry one of the characters of a pair, but not both.
In Mendelian language the individual animal or plant is called a _sygote_. If the two gametes that go to make a zygote carry the same character, the zygote is called a _homosygote_. If they carry opposite characters it is called a _heterosygote_.
By applying this theory to the results obtained by crossing the tall and dwarf peas, we see how perfectly it accounts for them. The individuals of the first generation contain and produce gametes bearing the elements representing tallness and shortness in equal numbers, and the results we get in the second generation are simply due to the segregation of these elements. As Bateson has remarked, the most striking consequence of Mendelian inheritance is the paradox that pure individuals may be bred from impure ones. Once the opposite character has been eliminated the individuals remain pure for any number of generations. Recent investigation suggests that the dominant may owe its dominance to a _factor_ which is absent in the recessive ; therefore we are not concerned with two opposing factors, but the presence or absence of a single factor. When the heterozygote is intermediate, we have no means of knowing in which of the two pure kinds of individuals the factor resides.
The Mendelian scheme of inheritance has been found to hold good for a great diversity of characters in plants and animals such as the absence or presence of horns in cattle, the pea comb and the single comb in fowls, the absence or presence of the waltzing habit in mice, and susceptibility or resistance to rust-disease in wheat, to mention only a few.
So far, we have considered the case of only one pair of differentiating characters in an individual, but the same results occur in the case of any number of pairs of characters. In the case of two pairs of differentiating characters we get, in the first generation of the hybrids, individuals all showing the two dominant characters. In the second generation we get nine individuals showing both dominants, three showing one dominant and one recessive, three showing the other dominant and the other recessive, and one showing both recessives. But it is not so easy to trace the results when there are several interacting factors modifying the same part or structure, or when the factors concerned fail to correspond with the characters that appear in the zygote, such as factors for inhibiting or developing colour,
Further complications are met with as the result of the repulsion and coupling of certain factors, including sometimes the factors for sex, the inheritance of which in some cases it appears to be possible to express in Mendelian terms. It is often hard to trace the inheritance of utility characters because they frequently are the result of many factors with differences so fine that they can hardly be recognised.
The study of Mendelian in the bee is hampered by several special difficulties. First, we cannot control mating in the ordinary way. Then there is the parthenogenetic production of the drone, which is likely to have a disturbing effect. Thirdly, the honey -bee is a highly specialised animal, and varies very little. There is some variation in size, the eastern races being smaller than those of the west, but apart from this the colour of the upper or dorsal side of the abdomen is the only visible character that varies strikingly. The variation consists in the extent to which the two colours, yellow and black, displace one another.
Turning our attention, firstly, to the workers, we find that in _Apis indica_, and in the artificial varieties known as golden bees, the yellow extends over the three basal Figure 34: Diagram showing Colouring of abdomen of Workers and Drones.
Fig. 34a.
Diagram showing Colouring of abdomen of Queens.
segments, and more or less of the basal part of the fourth segment. The scutellum on the posterior part of the thorax is also yellow. Extreme goldens, with the fourth segment entirely, and the fifth segment more or less, yellow, have also been bred, but it appears that they do not breed true. In Italians the three basal segments are bordered at the edges with black and the scutellum is darker. Italians from the Swiss Alps have the black bands wider than Italians from the Ligurian Alps, while Cypians have them narrower. Races with the abdomen entirely black occur in Britain, France, Germany, Malta and other places.
From igor to igrz I was engaged, at Ripple Court Apiary, near Dover, in breeding a golden bee, to which I gave the name "British Golden." This bee was extracted from crosses between English blacks, Italians and American goldens. The golden character was soon isolated, and thence-forward it was found possible to maintain the pure golden breed by breeding from queens that produced all goldens, though, as may be imagined, many of the queens were mated with blacks and produced hybrids. No attempt was made to increase the area of the golden colour. The diagram (Fig. r in Fig. 34) shows the colouring of the abdomen of a pure British Golden worker. It is interesting to compare this with Fig 4, which is the colouring of the abdomen of a pure British Golden queen. It will be seen that the yellow in the queen extends much further than in the worker. The factor,1 or factors, that produce a half yellow and half black abdomen in the worker produce an almost entirely yellow one in the queen. There is no difference in the gametes; the difference is merely a fluctuation in the zygote caused by a difference in the quality and quantity of food supplied in the larval stage. Since the work of breeding British Goldens was begun in Ripple Court Apiary, in igor, a very large number of pure golden queens have been bred; about i,500 of them were kept until their young workers hatched, and notes were made of the colouring of these. These workers were of two types only, golden and intermediate (see Figs. r & z in Fig. 34). Not a single black worker was seen. Most queens produced a considerable proportion of each type, but some produced all goldens, and some all intermediates.
It was evident that the queens that produced all goldens had been mated by a pure golden drone, and this was confirmed by the fact that the all-golden families were most numerous (1) from the matings that took place at the end of each season, namely, in August and September, when most of the drones in neighbouring apiaries had been killed off and only the golden drones in Ripple Court Apiary remained, and (2) from the matings that took place in cool and windy weather, and, therefore, close to the apiary.
Matings of the latter kind I have called by the name of "restricted matings." Most of them did not take place until the queens had been hatched twelve to fifteen days.
Fig. 35.
Diagram showing how a slightly restricted range of flight may completely isolate an apiary for breeding purposes. The dots represent imaginary apiaries, and the circles ranges of flight. The ranges of flight of queens and drones are not shown separately.
Ripple Court Apiary is a very favourable spot for restricted mating. The surrounding country is rather destitute of trees, and is much swept by cool winds, the prevailing north-easterly and south-westerly winds both blowing off the open sea, which is four and seven miles off in these respective directions. Perfectly calm days are rare. On sunny days in summer, when it is warm inland, the maximum temperature is generally about 5 degrees to 10 degrees lower and the wind stronger than in warm places inland. But there is more sunshine and the nights are warmer than inland.
## 62 Queen-Rearing in England.
The apiary is sheltered from wind by a belt of trees and shrubs, chiefly Austrian pine, goat willow, sycamore, and lime. Whichever way the wind blows, there is a sheltered area just outside the apiary in which, I believe, many queens have been mated. No bees are kept within half a mile of Ripple Court Apiary.
There was also evidence to confirm the opinion that the families consisting of all intermediates were the result of the union of the golden queens with pure black drones. Such families were not very numerous from matings that took place in Ripple Court Apiary, but out of five queens mated at a spot nearly two miles from the apiary four produced all intermediates, and one about nine intermediates to one golden.
Among the families that consisted of both goldens and intermediates, which it is reasonable to suppose were the result of mating with heterozygous drones, the two types appeared in varying proportions. A common proportion was about seven goldens to three intermediates, perhaps two to one, but the intermediates were sometimes in excess of the goldens. A case of go per cent, intermediates has just been referred to; and, at the other extreme, it may be mentioned that in 1912 I bred from a queen that produced about thirty goldens to one intermediate; the proportion of goldens to intermediates was the same in her queen progeny as in her worker progeny, and this has been so with every queen from which I have bred.
The queen corresponding to the intermediate worker is shown at Fig. 5 (in Fig. 34). Notice that she, too, is somewhat yellower than the corresponding worker, and that her scutellum is black, not yellow, as in the golden queen. The worker offspring of about thirty of these intermediate queens were examined, and in every case they consisted of goldens, intermediates, and blacks, thus proving that segregation of golden from black takes place. The proportions of the three forms varied in different cases, but the intermediates were usually greatly in excess of the goldens and the blacks. In many cases almost every degree of colouration between golden and black appeared, but not in equal numbers.
Out of 475 workers produced by an intermediate queen bred in Ripple Court Apiary in 1912, practically every degree of colour occurred.
Eleven had the first three segments of the abdomen yellow, but the edge of the second segment slightly darkened, more so at the sides, and the third segment narrowly edged with black.
Forty-seven had the second segment narrowly edged with black, the third segment broadly so.
Two hundred and fifty-two had the first segment also narrowly edged with black, and the second and third segments more widely so.
Six had the abdomen black, with a yellow smudge across the second segment.
Sixteen had it black, with a large yellow spot on either side at the base.
Twenty-nine had it black with a small yellow spot on either side at the base.
One hundred and fourteen had the abdomen entirely black.
Out of eighty-three workers produced by a lighter intermediate queen, also mated this season, nearly every degree of colour was found, but the proportions were different.
Six had the first three segments yellow, the third being narrowly edged with black.
Ten had the second narrowly, and in the middle faintly, edged with black, and the black edging of the third segment wider.
Fifty-two had the first segment narrowly edged with black, and the second and third segments more widely so.
One had the first segment tinged with black, and the second segment broadly edged with black.
Six had the abdomen black, but a spot on either side of the second segment at the base yellow.
Eight had the abdomen entirely black.
A few Italian drones were flying in the apiary in 1992 (the first occasion in ten years), and one or both of these queens may possibly have been mated by one, but I do not think it probable.
In trying to analyse all these results, we find ourselves in the dark on a most important point, the drone fathers.
## Chapter 6 Queen-Rearing in England.
But we can see that they indicate Mendelian inheritance. Indeed, up to a certain point, the simple Mendelian rule seems to be followed. The golden queen mated by the black drone produces the heterozygous intermediate. Mated by the intermediate, she produces goldens and intermediates, but no blacks (see Fig. 33). Again, the intermediate mated by the intermediate produces a small number of goldens, a large number of intermediates, and a small number of blacks. But the appearance of every grade of intermediate in the second generation shows that we are here probably dealing with more than one factor, though, as Punnett has shown in the case of the cross between a "Silky" hen and a "Brown Leghorn" cock, there need not be more than two if it be assumed that they interact on one another in different ways and to different degrees.
It seems unprofitable to speculate further as to the inheritance of the golden and black characters in queen and worker till more evidence has been collected, and we may turn our attention to the more practical question of how far Mendelism can help us in our efforts to improve the bee. A lesson it teaches us--that is, perhaps, of greater immediate value than any other--is that if the characters that we want depend on the heterozygous nature of the heterozygotes, the way to get them is to breed together the two pure homozygotes. Thus from the union golden x black we get all intermediates, whereas from the union intermediate x intermediate we get only a proportion of intermediates.
Fortunately, hampered as bee-breeding is by great difficulties, the particular union, golden queen x black drone, is practically attainable on a large scale, and, more fortunate still, the intermediate produced by it does possess certain qualities that are very desirable. In the first place, as in the case of heterozygotes in many plants and animals, it possesses the added vigour due to the crossing. This vigour shows itself in great energy, hardness, and industry in honey gathering. The hybrids produce larger average yields of honey per colony than blacks. They are considerably larger than goldens (in both queen and worker) and slightly larger than blacks. With the cross under consideration, golden queen by black drone, which is theonly practicable one in England (the reciprocal cross, golden \(\mathcal{J}\) by black \(\mathcal{Q}\), being only a chance production), the colonies are very populous because they are headed by golden queens, which are more prolific than blacks. An undesirable consequence of crossing bees is the development of an increased tendency to sting, but in this particular cross the temper is usually good, though it becomes hotter in later generations when the black colour predominates.
Reference has been made to the coupling of factors. Colour characters are often associated with various qualities of a useful nature or the reverse. Punnet states that the National Portrait Gallery furnishes remarkable evidence of this in man. Here the pictures of celebrated men and women are largely grouped according to the vocations in which they have succeeded. It is rare to find anything but _blue eyes_ among the soldiers and sailors, while among the actors, preachers, and orators the _dark eye_ is predominant, although for the population as a whole it is far scarcer than the light.
In the honey-bee several qualities are associated with the golden and black colours. The goldens are more prolific, they are also less hardy and smaller. They make a peculiar singing sound when they are smoked. These characters I have found inseparable from goldens. It is said that goldens are greater robbers than blacks, and that they distribute themselves more to neighbouring hives, but this I have not proved, and it is certain that they are more often detected doing these things on account of their bright outstanding colour than they would be if they resembled the bees whose hives they enter.
As regards desirable utility characters that are separately inherited, we are not in the near future likely to make much progress in unravelling the factors that stand for them, and even if we could do so, how can we fix them without controlling mating by isolation? In England there seems to be only one way, namely, by getting the character in our golden bee. During the last few years I have been trying to fix certain desirable qualities in my goldens. Having found the desirable quality in a stock, one must be prepared to sacrifice all one's other goldens in order to give it a chance to get fixed.
By, every year, wintering 3o to 5o of the purely mated British golden queens bred the previous year, carefully comparing their colonies for hardness and honey gathering in May and June, and breeding queens and drones from the best only, I was able to get some improvement in these directions, and a better bee for crossing with blacks.
A valuable lesson that Mendelism teaches to breeders of all kinds of plants and animals, and one that the bee-breeder must not lose sight of, is that, in the words of Punnett, "every possible variety arising from a cross appears in the second generation if only a sufficient number is raised, and of all these different varieties a certain proportion of each is already fixed." More can be accomplished by a careful analysis and isolation of the individuals of this generation than by years of breeding by selection on the old lines. The fear of losing the original variety by crossing it is unfounded, for it can be recovered in a fixed state with all the superadded vigour that follows from a cross.
We must remember that, underlying Mendelism, is the doctrine elaborated by Weismann : that characters acquired during the lifetime of the individual as the result of changes in treatment or environment cannot be transmitted to the offspring, though it is true environment may and does exert selection in individuals carrying different kinds of gametes. It is, therefore, useless to try to fix acquired characters--fluctuations, as they are called--by breeding, unless the treatment that causes them is always applied, as in the case of worker characters as distinguished from queen characters.
Robbing is generally an acquired character caused by carelessness on the part of the bee-keeper. Bad temper induced by improper handling is another case of an acquired character. Such characters, acquired by accident, need cause us little concern.
Most of the characters in the bee that we wish to improve are in the workers. How, it may be asked, can these be propagated, seeing the workers are sterile? We must do it through their reproductive sisters--the queens. It is comparatively easy to propagate the character if it is recognisable in the queens, even though much changed, as, for instance, the colour character. But we may wish to propagate a character that is not recognisable in the queen, such as industry. We may wish, for instance, to get the queen containing the factors carried by a particularly industrious worker in a live where most of the workers are less industrious. Unfortunately, we have no means of discovering such a queen, and characters of this kind that show themselves in individual workers are almost sure to be lost unless we can find them in a large proportion of the workers in a colony. For such characters we are compelled to test our bees in colonies, not as individuals. This is rather a serious limitation, for while we can study the characters of thousands of individual workers, comparatively few colonies are available. On the other hand, the enormous number of workers that a queen produces helps us very much in the study of what gametes she is producing, and as they are always surrounding her and continue to be produced for years, we can study them at leisure.
And here I may make a few remarks on estimating the proportions of the different coloured offspring of a queen. My practice is to do this, if possible, on the twenty-second or twenty-third day after the queen begins to lay. Then only a few hundred of her workers have hatched, and they can be distinguished at once from the other workers in the hive by their downy, soft, and immature appearance. At this stage one can, with practice, estimate fairly accurately almost at a glance the proportions, if only two types are present. Often there is a risk of robbing, and then it is not safe to keep the hive open more than a minute or two. Later, when there are workers in all stages of immaturity, it is less easy to estimate the proportions. It is not usually possible to ascertain the proportions from mature bees until the spring, and then the results may be rendered inaccurate by the presence of bees from other hives. For accurate work it is best to chloroform a few hundred bees, and then pick out the young ones and count out the different varieties of them before they have time to recover.
This incomplete separation is additional evidence of the presence of more than one factor for colour. In review of the situation, the production by a golden queen of dark drones cannot be said, in the light of our present knowledge of the inheritance of colour, to upset the universally accepted and apparently well-founded theory that the drone is always produced parthenogenetically, but, in view of the fact that in all our efforts to breed bees this theory plays a leading part in guiding the operations, such cases as this that seem to shake it should receive the fullest investigation. If we could control mating they would be certain to add valuable facts to our knowledge of the inheritance of sex.
Fig. 7 is of an Italian drone bred from a queen received from Bologna. Some of the drones produced by this queen had a more distinct tinge of yellow on the second segment, but none showed so great an extent of yellow as that exhibited by the British golden drone. It was the great variation in the colouring of the Italian drone--some are almost black--that led Perez's critics--for his statement raised a storm of opposition--to reject his idea of hybridism.
The inheritance of colour in the Italian bee is remarkable in two ways. First, the workers all come perfectly true to a colour pattern very like that of the cross between golden and black, though somewhat darker as a rule, and varying in different localities. Secondly, the queens, on the contrary, show immense variation : some are almost as yellow as goldens, though they lack the yellow scutellum and they have at least traces of dark spots on the segments. Others are broadly banded with black and have the last segments black. Are these differences in the queen mere fluctuations, or do they stand for factors in the gametes which do not manifest themselves in the workers?
settling. It is possible that this erratic behaviour is the result of the commencement of a disassociation of the units that go to make up the swarming impulse.
"Stingless " bees, in the sense that they do not insert their stings into human beings, are common in Asia, and there seems to be no reason why they should not be acclimised in Britain or in any other bee-keeping country. When investigating the bees of India, in 1897, I paid a visit to the apiary of native bees kept at the gaol at Darjeeling (altitude 7,000 feet), in the Eastern Himalayas. These bees were always handled without the use of either smoke or veil. I myself examined a hive in this way, and I handled the bees roughly to see if it was possible to get them to sting, but it was not. An angry swarm gathered around mv hat and head, and after I had left the hive twenty or thirty bees followed me wherever I went, but I gradually got rid of them by dodging behind bushes.