226 



AMERICAN BEE JOURNAL 



June 



queenbee have 32, while those of the 

 drone have only 16. 



Usually, before fertilization, the 

 male and female germ cells pass 

 through a preparatory process dur- 

 ing which the number of chromosomes 

 is reduced one-half and at fertiliza- 

 tion, therefore, the union of the egg 

 and sperm gives rise to a cell having 

 the characteristic number of chromo- 

 somes, one-half coming from the 

 mother and one-half from the father. 

 The peculiar odd chromosome may be 

 present in the fertile egg from only 

 one parent, or from both parents, and 

 it has been found that the pairing of 

 this body from both parents always 

 results in the new individual being a 

 female. The male results from an 

 egg bearing only one X chromosome. 



In the honeybees, the process of 

 parthenogenesis (virgin birth) gives 

 an unusual result, because the un- 

 fertile egg of the queenbee is able to 

 produce a new individual, but since it 

 cames only one of the X bodies, from 

 the mother, this individual is always a 

 male. The sperm of the drone also 

 always carries one X body and its 

 union with the X body in the egg of 

 the queen, therefore, always gives 

 rise to a female. This easily explains 

 the peculiar phenomenon so confus- 

 ing to beekeepers but so valuable in 

 breeding. 



Mendelism 



Scientific breeding has been devel- 

 oped from the investigations of Gre- 

 gor Mendel, an Augustinian monk, 

 who first published his results in 

 1865. Essentially, Mendelism is an 

 attempt to explain heredity on a sta- 

 tistical basis, and its operation is best 

 illustrated by some of Mendel's own 

 experiments. By crossing tall and 

 dwarf sweet peas he obtained hybrid 

 plants, all of which were tall like the 

 tall parent, but when the seeds from 

 these tall hybrids were grown, three- 

 fourths of the plants were tall, like 

 the original tall variety, and one- 

 fourth were dwarf, like the original 

 dwarf variety. Continuing the ex- 

 periments, Mendel found that these 



dwarf plants of the second generation 

 bred true, producing only dwarf 

 plants; but of the tall plants, one- 

 third only bred true, the other two- 

 thirds producing three-fourths tall hy- 

 brids and one-fourth dwarfs. 



Mendel studied hybrids involving 

 several pairs of contrasting characters 

 and found that, in every case, one 

 member of each pair of characters 

 was expressed unchanged in the hy- 

 brids, whereas the other member of 

 the pair became latent, and its pres- 

 ence could only be detected by grow- 

 ing the progeny of the hybrids. Those 

 characters, which were expressed un- 

 changed, Mendel termed dominant 

 characters, while the latent ones he 

 called recessive. In the above ex- 

 periments, for example, tallness was 

 dominant and dwarfness was reces- 

 sive. The dominant character pos- 

 sesses a double significance, since 

 either a uniform progeny of dom- 

 inants can be secured or hybrid pro- 

 geny in which one-fourth of the off- 

 spring displays the contrasted reces- 

 sive chai'acter. 



Since Mendel's time a vast number 

 of experiments have been canied on, 

 using animals like rabbits, guinea 

 pigs, or white mice, which breed very 

 rapidly, and insects like the fruit fly, 

 which can be produced under artificial 

 conditions with great rapidity. The 

 principle of Mendelism has been 

 found to hold good in all. Recent ex- 

 periments by Wilmon Newell in the 

 breeding of selected queens and the 

 crossing of races show that the honey- 

 bee is no exception. He found that 

 pure Italian queens, mated to Carni- 

 olan drones, produce only Italian 

 drones, and Carniolan queens, mated 

 to Italian drones, produce only Carni- 

 olan drones, which is strictly in ac- 

 cordance with Dzierzon's theory. 

 However, the daughters of these hy- 

 brid queens produce both Carniolan 

 and Italian drones, produce them in 

 equal numbers and do not produce 

 any other kind. The practical appli- 

 cation of this is that the only test of 

 an Italian queen's mating is found in 



r3s^: 



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i^s^miM&^M^ 



A group of Italian railrnail ni n receiving instruction in l)eckcciiing from Inspcclui loseiili 

 Montagano, of the Construction Office at Vcllctri. Province of Komc. 



the color of the drones produced by 

 her daughters. The term "tested 

 queen," therefore, as it is ordinarily 

 used, is a misnomer, as far as pure 

 mating is concerned. 



Hereditary Characters 



Every breeding animal should be 

 absolutely perfect physically, since it 

 has been found that animals, physic- 

 ally defective at birth, are apt to 

 transmit their defects to their off- 

 spring. It is therefore necessai-y that 

 the breeding queen be absolutely per- 

 fect physically, and just as much at- 

 tention should be given to producing 

 and having, in the mating yard, only 

 the most mature and perfect drones. 

 Fertility and Fecundity 

 Fertility is of next importance. 

 The term signifies the ability of the 

 mother to produce active, living 

 young. Fecundity is used to desig- 

 nate the potential reproductive capac- 

 ity of the individual. In the mother- 

 bee it can be measured accurately 

 and directly by keeping a record of 

 the number of full frames of brood 

 produced during the season. A few 

 seasons' work of accurate record- 

 keeping will show that there is a wide 

 variation, even with the best selected 

 stock. In general, it will also be 

 found that queens of the greatest fe- 

 cundity are' those of the largest size 

 and the most perfect physical devel- 

 opment. 



The factors which affect fecundity 

 are varied. The environment of the 

 queen undoubtedly has much to do 

 with her egg-laying ability. For ac- 

 curate results, therefore, the queen 

 breeder must supply the proper equip- 

 ment, especially an abundance of 

 room in the brood-chamber, and plen- 

 ty of food, in order that there may be 

 no checking of egg production. 0th- 

 ei-wise how can he expect the queen 

 to demonstrate her ability? Get rid 

 of all cramped brood-chambers, small 

 hives and baby nuclei. 



Inbreeding 

 Darwin concluded that all organic 

 beings benefit from an occasional 

 cross, and that the inevitable result 

 of continued inbreeding is loss of size 

 and a decrease in vigor and fertility. 

 At times, also, there is an increased 

 tendency towards malformations. 

 Recent investigations, however, have 

 shown that inbreeding, accompanied 

 by selection for high productiveness, 

 results in maintaining the fertility of 

 the race. It was also found, though, 

 that low fertility sometimes acts like 

 a Mendelian recessive, appearing in 

 alternate generations, and it would 

 seem, even from these experiments, 

 that inbreeding holds dangerous pos- 

 sibilities. 



Prepotency 

 It was an early observation of ani- 

 mal breeders that some animals pos- 

 sess a supei'ior power of impressing 

 their offspring with their character- 

 istics. This peculiar power is tei-uied 

 prepotency. The existence of prepo- 

 tent animals cannot be denied, al- 

 though by just what means the.r yve- 

 potency is expressed has not yet been 

 determined. Bees are no exception, 

 since we have instances of gi-eat fer- 



