302 DR. В. М. SALAMAN ON MALE STERILITY IN POTATOES : 
In these families all the flowers were examined, with the following 
results :— 
Pollen present. Pollen absent. 
Н! x A ......... 7 12 
HY x À......... 12 8 
Total ...... 19 20 
The expected ratio being equality. 
It is to be observed that of those possessing pollen only seven are classed 
as containing a ** medium " quantity; the remainder have all small quantities. 
Moreover, the percentage of dead grains throughout is very high, and the 
quality of the recessive parent “ А ” is not fully reproduced. 
Congo х Flourball.—-In this ease * Congo” is quite sterile. The anthers 
are not aborted. Е! consisted of 23 individuals, of which five had no flowers, 
and of the remaining 18, eight had *abundant" pollen and ten none at all. 
Two of the F! were selfed with the following results :— 
Pollen present. Pollen absent. 
KE ........... us 36 3 
ky, 8 0 
Total ...... 44 3 
Theoretically all should contain pollen, but three plants with normal 
anthers contained none. Of the remaining 41 plants, four have little, two 
medium quantities, and thirty-five abundant. 
I have at present no explanation to offer for this discrepancy. That 
“Congo” is heterozygous for sterility is further shown by a second cross, 
where ** Reading Russet ” was the pollen parent. Неге only three К! plants 
flowered, two contained small quantities of pollen, and one none. 
Red Fir Apple x Reading Russet—Red Fir Apple has а small pale 
heliotrope flower with entirely contabescent anthers. Reading Russet bears 
an abundance of pollen. Only nine Е! plants were preserved in 1909, when 
these pollen observations were being made. Of these, six had no flowers, 
two had plenty of pollen, and one noue. In F?, of six plants examined, in 
1909, all have pollen present. In 1910, 22 more Е? plants have flowered and 
all possess a quantity of pollen. 
Queen of the Valley x Flourball—Queen of the Valley has heliotrope 
flowers with pale anthers, having only very little pollen, and that all aborted. 
The ЕЁ! family were not specially watched for pollen, but there is evidence 
