PAENELL, RANGASWAMI AYYANGAR, AND RAMIAH 91 



The full-purple character is obviously due to the presence of a simple 

 factor, irrespective of any other colouring that may be present in the sheath. 

 A good deal of variation in intensity of colouring exists in the dominant group 

 and this proved to be partly due to the heterozygotes showing, on the whole, 

 rather less colour than the pure dominants. The former could not be separated 

 as a definite group, however, owing to the fact that varying exposure to light 

 also affects the intensification of the colouring. 



(h) Purple lininc4 of internode, purple glumes, purple stigma, 



PURPLE AXIL. 



The above characters will be considered together, since, in certain crosses 

 in which they were all concerned, several types of gametic reduplication 

 occurred. 



Purple lining of the internode is due to pigment in the sheaths of the 

 vascular bundles. It is normally associated with a certain amount of Hning in 

 the leaf-sheath and it is possible that one factor determines both. It is a 

 common character, found in very many varieties, and shows great variation. 

 In'some types the lining is fainfc and scarcely noticeable, developing only when 

 the internode is exposed to strong light. Many intermediate forms exist 

 between such types and those showing the fullest development where the whole 

 internode is deeply coloured in shades varying from almost red to almost black. 



Such deeply coloured types are included under purple lining as examina- 

 tion shows that the pigment is present mainly in the bundle sheaths, although 

 ifc spreads into the surrounding cortex sufficiently to give the appearance of 

 self -colouring. 



There are imdoubtedly several factors concerned in the various types of 

 lining, but there appears to be considerable compKcation and they have not yet 

 been worked out. So far as concerns the present considerations the actual 

 type of lining is immaterial since all have behaved in the same manner. 



The purple glumes, character is somewhat variable. In all types noted the 

 small outer glumes are almost entirely purple. The inner glumes vary, in the 

 distribution of the colouring, from the type shown in Plate IV, B, 1, to one in 

 which they are imiformly puri)le. The actual colouring also varies from 

 ordinary purple to almost black. 



The factors concerned in these variations have not been worked out, but, 

 as in the case of purple lining, all types behave in the same manner in their 

 relations considered below. 



The type of purple stigma under consideration is shown in Plate IV, B, 23. 

 Other types exist but are not included in this account. 



