940 



SCIENCE 



[N. S. Vol. XLIII. No. 1122 



If the constitution of a pure Italian queen be rep- 

 resented by II and of a pure Caruiolan queen by 

 CC, the former will produce gametes I and I, and 

 the latter, gametes C and C, these being Italian 

 and Carniolan drones respectively. (?) 



These conclusions of Professor Newell are 

 not verified in so far as I have been able to 

 judge from the results obtained by breeding 

 tests that I have made in various ways with 

 drones reared from heterozygous queens. The 

 GuK Coast prairies near Houston, Texas, are 

 ideal for the complete isolation of mating sta- 

 tions. With little difficulty locations can be 

 found where there are no trees or shrubs of 

 sufficient size to harbor a swarm, within a 

 radius of from five to seven miles, which allow 

 matings to be made with a reasonable degree 

 of certainty. 



To determine the behavior of the color fac- 

 tor in transmission, a pure strain of golden 

 Italians and gray Caucasians (bred from 

 queens that I imported) were chosen with 

 which to make the primary or initial cross, the 

 former giving workers of the brightest yellow 

 color, while the workers of the latter are dis- 

 tinctly gray without a trace of yeUow on the 

 abdominal segments. 



The result of mating a golden queen to a 

 Caucasian drone is shown by the following 

 scheme. 



Golden 

 queen 



gametes 



Zygotes 



FFIIcc ffCCii 



FIc 1 -. ( fCi 



Flcl ^ tfCi 



Caucasian 

 drone 



1 III 



FfliCc FfliCc FfliCc FfliCc = F, 



all heterozygous females, colored like ordinary 

 Italian workers, showing that yellow is domi- 

 nant to gray, a result agreeing entirely with 

 Professor Newell's observations of the F^ Ital- 

 ian-Carniolan Cross. The gray (dark) or re- 

 cessive color does not appear in this genera- 

 tion of workers, the reciprocal cross gives the 

 same results. 



When queens are reared from these Fj 

 larvae they produce drones of the constitution 

 liCc the same as the mother, a fact verified by 

 subsequent breeding tests. The following 

 scheme shows the result of mating a heterozy- 

 gous queen to a heterozygous drone. 



heterozygous heterozygous 



queen FFIiCc ffliCc drone 



Zygotes 



FiC \ _ ( fic 



FIc / ~ I fiC 



Ffllcc FfliCc FfliCc FfiiCC = Fj 



females, as will be observed, segregation occurs 

 in this generation in a true 1:2:1 Mendelian 

 ratio, or one pure dominant, two heterozygous 

 dominants and one pure recessive, a result 

 similar to that observed by Mendel in the Fj 

 of his cross of a tall pea on a short or dwarf 

 variety, in which he got one TT, two Tt, Tt 

 and one tt, or (dwarf) recessive; so it is in 

 the case of the F^ workers, in appearance there 

 are three that show the dominant or yellow 

 color of the Italians and one in four is reces- 

 sive, or gray in color. This feature is mark- 

 edly noticeable when queens are reared from 

 larvse of this generation; of the number 

 hatched, about 25 per cent, show the pure 

 golden color, 50 per cent, appear as ordinary 

 Italian queens, with about the same variation 

 in general color (that these are heterozygous 

 in constitution is proved when bred to reces- 

 sive drones) and 25 per cent, of them show 

 only the recessive color, and in subsequent 

 breeding prove to be pure recessives and con- 

 tinue to breed true when mated to recessive 

 drones. The diSerences in the color of the 

 workers of this F„ are not so accentuated as 

 in the queen reared from the same larvae. As 

 shown the pure dominant queens are golden, 

 the impure dominants intermediate in color, 

 while the recessives are gray without any 

 trace of yellow on the abdominal segments. 



Since drones are produced parthenogenet- 

 ically, we must consider the fact that the egg 

 of the queen at maturation, when not fertil- 

 ized, is reduced from the 21sr (or NN) condi- 

 tion to the 21^ — 1 (or 21^ — 2) condition, show- 

 ing that a whole set, N, of chromosomes is not 

 eliminated in maturation, but only one or two 

 chromosomes. Hence the male condition here 

 is 2N — 1 or — 2. The condition of the ga- 

 metes formed, however, is IN" in both sexes. 

 Since in fertilization only ^N zygotes are pro- 

 duced, they are (in the case of bees) invariably 

 females. 



