POLLINATION AND STERILITY 



287 



256. Longevity and viability of pollen. — At present there 

 is considerable difference of opinion in regard to tlie lengtli 

 of time pollen remains viable. One investigator ^ records 

 interesting observations on the longevity of pollen secured 

 from widely different sources, namely, Washington (state), 

 Tennessee, Missouri, and Mimiesota. Part of the samples 

 were on the road four to five daj^s but arrived in "perfect 

 condition." Germination tests on its arrival showed all 

 samples to be practically normal. It was then placed in the 

 laboratoiy in a temperature ranging from 10° to 18° C, 

 and tests were made each month for six months with 

 the exception of the last, which was eight months after 

 its arrival. The following data show the results of this 

 test: 



Table LXXXV 



LONGEVITY OF APPLE AND PLUM POLLEN. (AFTER SANDSTEN) 



Sandsten, E. P. Wis. Agr. Exp. Sta. Tech. Bull. 4. 1909. 



