Volume X AUGUST, 1920 No. 2 



INHERITANCE IN BARLEY. 



I. THE LATERAL FLORETS AND THE RACHILLA. 



By F. L. ENGLEDOW. 



(With 3 Text-figures.) 



CONTENTS. 



PAQK 



Introduction . 93 



I. TheRachilla 94 



II. The Lateral Floret 98 



III. The Inheritance of the Lateral Floret .... 100 



IV. The Problem of Inheritance in Lateral Florets . . 103 • 



Appendix . 106 



Bibliography 108 



Introduction; 



This account of the inheritance of certain of the characters of barley 

 is to be regarded as provisional. It represents the results of observa- 

 tions made from time to time upon F^'s which have been raised for 

 plant breeding purposes. 



The " lateral floret " has become a familiar problem in barley genetics. 

 It is believed that although the general solution of this problem has 

 been reached, there still remain a number of interesting side issues 

 which can be decided only by raising large and complete ^3's and by a 

 histological study of the various degrees of development of the floret. 



That the artificially produced variety H. inerme (obtained by Rimpau 

 from the cross H. Steudelii x H. trifurcatum) offers a complete solution 

 to the problems of the inheritance of awn and lateral floret seems 

 certain ; but H. inerme fluctuates very readily under environmental 

 change and for this reason the evidence obtained so far from its crosses 

 has not been used in this paper. A study of the seasonal fluctuation of 

 H. inerme and of the two " intermediums " {H. Haxtoni and H. tran- 

 siens) is, as crosses have repeatedly demonstrated, essential to finality 

 in the elucidation of the awn and lateral floret problems. 



Joorn. of Gen. x 7 



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