THE INHERITANCE OF SIZES AND SHAPES IN 

 PLANTS 



A Preliminary Note 1 



PROFESSOR R. A. EMERSON 

 University of Nebraska 



Some years ago Lock reported a cross of a tall race of 

 maize with a shorter race which produced an intermedi- 

 ate height in F x and exhibited no segregation in F 2 when 

 crossed back with one of the parents. 2 Castle's results 

 with rabbits are very similar to those of Lock with maize. 

 Castle summarizes his results in part as follows: 3 



A cross between rabbits differing in ear-length produces offspring 

 with ears of intermediate length, varying about the mean of the 

 parental ear-lengths. ... A study of the offspring of the primary 

 cross-breds shows the blend of the parental characters to be permanent. 

 No reappearance of the grand parental ear-lengths occurs in generation 

 F 2 , nor are the individuals of that second generation as a rule more 

 variable than those of the first generation of cross-breds. ... It seems 

 probable that skeletal dimensions, and so proportions of skeletal parts, 

 behave in general as blending characters. The linear dimensions of the 

 skeletal parts of an individual approximate closely the mid-parental 

 dimensions. 



From his own work with rabbits and Lock's work with 

 maize, Castle offers this somewhat guarded generaliza- 

 tion : 4 



It is probable that in plants, as well as in animals, linear dimensions 

 are in general blending in their inheritance. . . . The obviously blend- 

 ing inheritance of height in this case [maize] does not contradict the 

 known Mendelian behavior of the growth habit in such plants as the 



of plant physiology f the Graduate School of Agriculture, Ames. Iowa, 

 July 8, 1910. The complete records are to be published later by the Ne- 



2 Lo<-k. R. TF.. Ann. Hoy. Bot. Gaul. Paradeniya, 3 (1906), p. 130. 

 •Castle, W. E., et al., Carnegie Inst., Pub. No. 114 (1909), pp. 35, 43. 



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