Volume Vll AUGUST. 1918 No. 4 



THE INHERITANCE OF TIGHT AND LOOSE 

 PALEAE IN AVENA NUDA CROSSES'. 



By a. St CLAIR CAPORN. 



(With six text-figuves.) 



Experiments were conducted with three varieties of ordinary oats 

 with tight paleae, viz. : — 



Thousand Dollar. 



Ligowo. 



Nubischer Schwarzer (Nubian Black). 

 As the F.2 generation of the cross with Nubischer Schwarzer has not 

 yet been harvested, being part of this year's crop, it may be necessary 

 to issue the results obtained from it in a supplementary account, though 

 reference to its earlier stages will be made in this paper. 



A short description of each of the parents will indicate the nature 

 of the characters involved. 



Thousand Dollar. 



This is a typical tight grained oat of the spreading, or open, panicle 

 kind. The gi-ains are of good size, fairly long, and firmly ensheathed 

 in the paleae. They do not, except when it is exceptionally prolonged 

 and violent, become naked on threshing. The inner paleae are thin 

 but stiff, the outer thick and curled round the edges of the inner. So 

 well developed is the intervascular sclerotic tissue that the fine longi- 

 tudinal ribs of the outer paleae appear only as faint markings, the 

 whole surface, save at the extreme tip, being perfectly smooth. 



The spikelets are usually two-grained, though a panicle will often 

 contain a few which are 3-grained. Very rarely a plant will be found 

 which has two or three 4-grained spikelets. In this case the upper- 

 most grain is generally very small and all the peduncles are short and 



1 The work herein described was taken up at the b\ stage. Tlie data concerning the 

 parents and the F] generation, however, were rather vague and scanty, and had to be 

 reinvestigated by me concurrently with the analysis of the F^ crop. 



Journ. of Gen. vii 16 



