PARNELL, RANGASWAMI AYYANOAR, AND RAMIAH 77 



Hector^ working in Lower Bengal, finds that dehiscence of the anthers 

 normally takes place at the moment of opening of the glumes whilst the stigmas 

 are still enclosed. He estimates, provisionally, that cross-fertilization may 

 take place to the extent of about 4 per cent. 



Graham^ states that in five years' work at Nagpur, during which many 

 different varieties were grown in adjacent lines, no case of natural crossing 

 was detected. 



McKerraP shows that in Lower Burma a certain amount of crossing 



undoubtedly takes place. His figures in connexion with the crossing 



of white rice by red [1. c. p. .326) indicate about 4 per cent, of total cross- 

 fertilization. 



Thompstone^ notes that in Upper Burma " pollination takes place before 

 the glumes open, or at the moment of opening — seldom afterwards." He 



finds that " hybrids are quite common among the numerous rogues to 



be found in nearly every field of ordinary paddy " 



Observations made at several places in the Madras Presidency show that 

 there is some difference between different varieties. Most commonly dehiscence 

 does not take place till the glumes are well open and the anthers are partially 

 extruded. Very exceptionally dehiscence takes place immediately before or 

 during the opening of the glumes, whereas occasionally it is postponed till 

 some seconds after the anthers have assumed a pendent position. In some 

 cases it has been found possible to perform successful emasculations, for cross- 

 ing purposes, by allowing the glumes to open naturally and removing the 

 anthers as they emerge. 



The amount of cross-fertilization taking place naturally was estimated 

 for several varieties. In each case a variety was chosen which normally 

 possessed a purple tip to the grain, but in which occasional plants altogether 

 lacking in purple colouring were to be found. It will be seen later that such 

 green plants are pure recessives, so that any purple-tipped plants in their 

 progeny must be due to crossing. A few of these pure green plants, surrounded 

 by the purple-tipped type, were picked out and allowed to set seed naturally. 

 Their progeny contained a small number of purple-tipped plants which were 

 counted and calculated as a percentage of the total number as shown in Table I. 



^ Hector, G.'P., Mem. Depl. of Af/r. in Jndin. Hot. Series, vol. VI, no. 1. 



2 Graham, R. J. D., I. c, p. 214. 



3 McKerral, A., Agr. Jl. India, vol. VIII, 1913. p. 317. 

 ^4 Thompstone, E., Agr. Jl India, vol. X. 1915, p. 26. 



