THE THBEE FOBMS OF LTTHBTJM SAMCAHIA. 



181 



Table I. — Lono-sttlbd Foem {continued). 



in. 



IV. 



14 flowera fertUized by the short 



12 flowers fertilized by the shorter 



stamens of the mid-styled. 



stamens of the short-styled. 



3 



20 































— 



— 



a 















Too sterile for any average. 



Too sterile for any average. 





V. 



VI. 



15 flowers fertilized by oivn longer 



15 flowers fertilized by miM shorter 



stamens. 



stamens. 



2 — 



4 — 



10 



8 



23 



4 



. 







































Too sterile for any average. ' 



Too sterile for any average. 



I fertilized a considerable number of flowers with pollen, taken by a 

 camel's-hair brush,fi-om both the long and short stamens of their own (long- 

 styled) form ; but I did not examine with a lens (as I did in the cases in 

 the Tables) whether suflicient pollen had been placed on the stigma : only 

 5 capsules were produced, and these jielded on an average 14'5 seed. In 

 186.3 I tried a much better experiment : a long-styled plant was grown 

 by itself, miles away from an}' other plant, so that its stigmas could have 

 received only the two kinds of pollen proper to this form. The flowers 

 were incessantly visited by bees, so that the stigmas must have received 

 on the most favourable days, and at the most favourable hours, successive 

 applications of pollen : aU who have crossed plants know that this highly 

 favours fertilization. This plant produced an abundant crop of capsules ; 

 I took by chance 20, and these (excluding one poor one) contained seed as 

 below:— 20 20 35 21 19 



20 24 12 23 10 



7 30 27 29 13 



20 12 29 19 35 



This gives an average of 21-5 seed per capsule ; and as we know that this 

 form, when standing near plants of the other two forms and fertilized by 

 insects, produces an average of 934 seed per capsule, we see that the 

 long-styled form fertilized by its own two poUens j-ields only between 

 one-fourth and one-fifth of the full number of seed. I have spoken as if 

 this plant had received both its own kinds of pollen, and this is, of course, 

 possible ; but, from the enclosed position of the shorter stamens, it is 

 much more probable that the stigma received almost exclusively the pollen 

 from its own longer stamens. 



