SPELTLIKE BUD-SFORTS IN COMMON WHEAT 



123 



the typical epidermis has been entirely replaced by the sp'eltoid. The 

 result is a periclinal chimaera of the normal type surrounded by a 

 heterozygote epidermis. > 



With the knowledge of the last described chimaera in mind it 

 would not be too much of a surprise 

 to find periclinal chimaeras with spikes 

 morphologically resembling speltoid hetero- 

 zygotes, but which, nevertheless, give rise 

 to a constant and typical progeny. This 

 »segregation» (when all the descendants from 

 a speltoid heterozygote become constantly 

 normal) could easily be incorrectly explained, 

 were the presence of these chimaeras not 

 known. We know that gamete elimination 

 in speltoid heterozygotes often occurs. There- 

 fore, it would certainly lie close at hand to 

 assume not only an elimination of male ga- 

 metes with speltoid character but also an eli- 

 mination of the speltoid female gametes in 

 some cases. This assumption would seeming- 

 ly correspond with the fact, that in the pro- 

 geny of a speltoid heterozygote only typical 

 plants arose, or — assuming partial elimina- 

 tion — that only ]ietei:ozygotes to so small 

 a percentage could be formed that in the 

 progeny of one plant only individuals of the 

 normal type appeared. 



Besides the already described chimaeras 

 I have found three other chimaeralike 

 plants, two of which unfortunately were 

 destroyed when harvested. The third, the 

 progeny of which I have studied, appeared 

 to be of another kind than those already 

 described. This particular one was discove- 

 red in the autumn 1917, in the material 

 from a plot (1917 — 965) with the F, genera- 

 tion of a cross between Sunwheat II and the Rumanian wheat sort 

 Blé Balan, both yy/gfore-types. Among 67 plants with spikes of normal 

 shape there appeared one plant, resembling at first sight a common 

 speltoid heterozygote. When examining it more closely, however, I 



Fi{{. (5. A chimaera from 

 the cross Sunwheat X H«- 

 manian wheat. The spel- 

 toid outer glumes of the 

 lowest spikelets marked 1, 

 11, III and IV. 



