8 THE MENDEL JOURNAL 



The first parthenogenetic seed I examined was 

 tliat of Nic. Tab. Cuba ; half the seed was round, full, 

 sound looking ; the other half flattened, poor, little 

 likely to germinate. The parthenogenetic seed was 

 compared with selfed seed of the same variety ; in 

 this latter nine-tenths was full, sound seed. It seems 

 possible that in this variety all the ovules are not 

 capable of parthenogenesis, and that those not set 

 might have proved fertile to a pollination either self 

 or cross. But in the hybrid Nic. Sylvestris x Nic. 

 afpnis F-i the parthenogenetic seed was all round, 

 full, and sound. 



In order to ascertain the condition of the pollen 

 in the Nicotiana buds, within about twenty-four 

 hours of expansion^ I gathered from Nic. Sylvestris x 

 Nic. Tab. Cuba Fi an unopened bud 2 Jin. in length, 

 and split it open ; the style was two-eighths 

 of an inch longer than the stamens, and the anthers 

 were green and solid. I cut one and placed the 

 section under the microscope ; the pollen was 

 miniature, and floated in a colourless liquid that 

 dried up after a quarter of a minute's exposure to 

 the air. As the anthers dehisce at the opening of 

 the corolla, the development of the pollen is 

 probably very rapid towards the end. 



The observation of the immature condition of 

 Nicotiana pollen in the young bud at a time subsequent 

 ■ to that chosen for the removal of the anthers and stigma 

 testifies both to the ease with which, in this plant, trials 

 for parthenogenesis'can be made, and to the reliability 

 of the experiments. 



