ZUR GENETIK DES WEIZENS 87 
4) In 3 cases: 
elimination ‘4, reduplication 4 or 
PNA Sp) X-d(8 N + 1 Sp) = 8 Norm. : 33. het. : 4*hom. 
But some heterozygotes produced by crossing show complete elimina- 
tion of ¢ Sp gametes so that no Speltoid homozygotes appear in 
the F,. 
9. Occasionally heterogamy can be shown in the Normal type 
and in Speltoid homozygotes as well, when these are heterozygotic 
in the awn factor. For Uu plants of Normal type three instances 
are given, and for Uu Speltoids one is reported by NizssoN-EHLE 
(1920, p. 283). 
10. In the offspring of Speltoid heterozygotes, plants of Compac- 
tum type occasionally occur; thus in a total progeny of 39,146 plants, 
184 were Compactum heterozygotes. In awned lines always awned, 
and in awnless lines always awnless, Compactum appeared. Besides, 
Compactum seems to appear in certain ratios in proportion to the 
number of plants of Normal type in the offspring, viz. : 16 Norm. : 1 
Comp., 24 : 1, 32:1, 48:1, 64:1 or in still lower proportions. 
11. The offspring of Typical compactum occasionally segregate 
in 1 Normal type: 1 Typ. comp. but generally in 8 Normal : 3 Spelt.- 
het.: 10 Typ. comp.: 1 Short comp. or thereabouts. Short compac- 
tum again yields an offspring of 2 Normal: 1 Typ. comp.:1 Short 
comp. or 1: 1:1 and sometimes seems to breed nearly true. 
12. From reciprocal crosses with Typical compactum we deduce 
the fact that the Compactum complex includes the Sp-complex so that 
it may be symbolized SpC, hence the zygote production by self polli- 
nation of this Comp. heterozygote should be 
2 (3 N4+1Sp+3 SpC)X J(8 N+1 SpC)— 
24 Norm.: 8 Spelt. het.: 27 Typ. comp.: 3 Sh. comp.: 1 Sq. het. 
Thus the Sp complex, which in the Speltoid-heterozygote was not 
carried over with the pollen, in Compactum is carried with the 
pollen in the binding Spc and in the proportion 1 f :3 2. But 
the Squarehead heterozygote is rarely found in the Compactum- 
progeny and Short compactum does not behave as a homozygote in 
SpC according to the formula, but rather as a double heterozygote in 
this character. With these symbols therefore the process is not exactly 
described but merely roughly sketched. 
13. According to the results from reciprocal crosses, the zygote 
production in the Square-head heterozygote can be indicated thus : 
