Cher ÄHRCtlENAltSTANO UND ÄHRCHEN/.AHL 299 



viz. one (TOSS hclwccn vuUjarc and Spvltd, reciprocal crosses between 

 compdctuni and Spvlta, two crossi's l»el\veen vuUjdre and liinjidum and 

 one cross between vnUjnrv and ilicocciim. Tbree generations were ana- 

 lysed. The total nuniber ot plants was about loOOO. The text con- 

 tains a discussion ol the general results. 



In the cross of vulgare X Spcltci (tables 1 — 10) the following tacts 

 were established. The Spt'lta-])h\i\ls had a greater internode-length and 

 a smaller number of sj)ikelets than the c(^rresponding vul(/(irc j)Iants, 

 the ditlerence being in the former case about 2 mm, in the latter 

 approximatively 2. The heterozygotes were intermediate in both 

 respects, yet with some tendency to the internode-length of Spclla and 

 to the number of spikelets of viilyare. The negative correlation 

 between internodi'-length and number of spikelets lound in the F; as 

 a whole could not be stated in the separate groups. 



The reciprocal crosses of compactiim y( Speltd (tables II — 14) 

 gave rise to four groups of homozygotic types, viz. compactiim, Spclta, 

 vulgare and compacto-Spelta — a quite new group — as well as to 

 different kinds of heterozygotes. The results obtained for Spelta and 

 vulgare resembled those gained through the above cross, the Spelta 

 gene obviously causing an increase in the internode-length and a 

 decrease in the number of spikelets. The compactiim gene is shown 

 to act in an opposite manner, for compactiim types had a smaller 

 internode-length and a larger number of spikelets than the correspon- 

 ding vulgare types. The Spelta gene behaved in a similar manner in the 

 presence and in the absence of the compactiim gene, and equally this 

 gene had the same effect when the Spelta gene was present as when it 

 was absent. The homozygotic influence of the compactiim gent' 

 seemed to be about as large as that of the Spelta gene, thus the types 

 of compacto-Spelta resembled the corresponding vulgare types as 

 to internode-length and number of spikelets. The heterozygotic effect 

 of the Spelta gene was rather small in progenies homozygotic as to the 

 compactum gene. 



In the crosses of vulgare X turgidum (tables 15 — 22) the following 

 groups of homozygotic types were obtained, viz. turgidum, durum. 

 vulgare and speltoides. As the group of durum is closely related to that 

 of turgidum the occurrence of the durum types is not peculiar. More 

 remarkable are the speltoides types which are to be regarded as re- 

 cessive products of the genetic combination. Some forms had very 

 narrow outer glumes; such types resembling vulgare in other respects 

 are called lanceolatum. The internode-length was rather small in 



Hereditas IV. -'* 



