314 Belling. 



embryo-sacs in this one ovaiy, as there was of pollen in the two last 

 China flowers examined in 1912. 



To sum up: — In the Velvet, L3'on, Yokohama, and China 

 beans, a few ovules abort, in some pods only. For the distal 

 halves of the pods the number varies near 10 per cent, and is, I con- 

 sider, due to unfavorable circumstances for those particular pods. From 

 about one tliird to a half (in number) of the pods are full of seeds, and 

 contain no undeveloped ovules. Sections of ovaries showed that 

 (except in one case) all the ovules had completely-formed 

 embryo -sacs. 



Fertility of the Hybrids (F,). 



Pdllen of the Hybrids (Fj). 



Velvet by Lyon. — Tliere are no records of the pollen being 

 examined in 1908. 



Lyon ])y Velvet. — I examined the pollen with the microscope in 

 1911, but no counts were made of full and empt}'^ grains. 



Velvet by Yokohama. — Pollen was examined from 10 flowers from 

 3 racemes in 1912. From one flower a count of several fields of 

 the microscope showed 415 full grains to more than 314 quite empty 

 and collapsed grains. Tliis is 43 per cent of empty grains. There 

 were no intermediate, half-empty grains. The pollen was examined in 

 a drop of alcohol, and gently spread by mo-^ing the cover-glass. Every 

 full grain was certainly counted; but some empty grains were hidden 

 under the full grains, or were swept into masses in which some of 

 them escaped the count. Each of the other 9 flowers had also about 

 half the pollen-grains empty. The large amount of bad gi'ains did not 

 appear to interfere with pollination, as 31 good grains were seen 

 embedded in the stigma of an unopened flower. 



Velvet by China. — One of the hybrid plants is shown in Fig. 7. 

 Pollen was examined fi'om flowers of the ten hybrid plants in 1913. 

 In every case about half the pollen consisted of large full grains, and 

 the other half of smaller, collapsed, quite empty shells (Fig. 8). Fig. 9 

 is a camera drawing (Zeiss' DD, Oc. 2) of the pollen in dilute al- 

 cohol, in wliich the Uve grains have swollen. Counts, of 69 fields of 

 the microscope, of pollen from several flowers, gave a total of 2135 full 

 to 1813 empty gi'ains, that is, 46 per cent of empty grains. Another 

 set of counts of 40 fields gave 1782 full to 1575 empty grains, that 

 is, 47 per cent of empty grains. These counts were made in alcohol, 

 and the percentage of empty grains is l)elow the true amount, for the 



