310 Belling. 



any particular plant of this generation is to be designated, its number 

 is written without a break, as, VY7. A hj-phen (-) separates successive 

 generations: thus, VL-515 is number 515 of the second filial generation 

 of the cross of Velvet by Lyon pollen. VL-515-27 is the twenty-seventh 

 plant of the third generation of the same family. VL-515-27-38-n is 

 the farm crop of this line in the fifth generation, selected to constancy 

 for all important agricultural features. 



Fertility of Parent Plants. 



Pollen-grains of Parent Plants. 



The pollen of the Stizolobiums is easily examined. It is held in 

 the closed cartilaginous tip of the keel. Tliis tip does not normally 

 open. Pollen-tubes grow into the viscid stigma from the grains which 

 become embedded in it. The flowers, in Florida, are functionally 

 cleistogamic , like the Pisum of our kitchen -gardens. When the apex 

 of the keel is split open on a glass slide, a mass of pollen extrudes, 

 which can then be examined under a cover- glass in absolute alcohol. 

 After heavj' rain, moisture may have caused some of the grains in some 

 flowers to burst; but these are easily distinguished from the smaller 

 naturally-empty grains. 



Pollen of the Velvet bean has many times been examined by the 

 microscope, and uniformly found to be good, even late in the season. 

 For example, on October 9, 1912, two flowers were examined. In one, 

 several fields of the microscope showed 36U sound grains and 17 more 

 or less empty grains. In the other flower also almost all the grains 

 were normal. On October 14, 1913, thirty-six flowers were examined, 

 and, except a few occasional empty grains, all pollen was good. Since 

 the Velvet bean begins to flower early in September, these were quite 

 late flowers. These flowers were taken from the pedigreed hne used 

 in crossing. 



Pollen of the Lyon beau lias always been found to be good, even 

 late in the flowering season. A flower was examined on October 9, 

 1912, and the pollen found to be nearly free from empty or partially 

 empty grains. Pollen of 22 flowers was examined on October 14, 1913, 

 and found to be uniformly good. These flowers were taken from the 

 pedigreed line of Lyon used in crossing. 



Pollen of the Yokohama bean has often been examined. The anthers 

 are liable to some, probably physiological, disease, which blackens them. 

 Moisture seems to enter the flowers of this ])lant rather readily. (Some- 



