Chap. IX. SELF-STEBILE PLANTS. 337 



A, C, or D, and all produced fine capsules. Eight 

 flowers were fertilised with pollen from other flowers 

 on the same plant, and produced no capsules. 



On the plants F and G no flowers were crossed, but 

 very many (number not recorded) were fertilised with 

 pollen from other flowers on the same plants, and these 

 did not produce a single capsule. 



We thus see that fifty-five flowers on five of the 

 above plants were reciprocally crossed in various ways ; 

 several flowers on each of these plants being ferti- 

 lised with pollen from several of the other plants. 

 These fifty-five flowers produced fifty-two capsules, 

 almost all of which were of full size and contained 

 an abundance of seeds. On the other hand, seventy- 

 nine flowers (besides many others not recorded) were 

 fertilised with pollen from other flowers on the same 

 plants, and these did not produce a single capsule. 

 In one case in which I examined the stigmas of the 

 flowers fertilised with their own pollen, these were 

 penetrated by the pollen- tubes, although such pene- 

 tration produced no effect. Pollen falls generally, 

 and I believe always, from the anthers on the stigmas 

 of the same flower ; yet only three out of the 

 above seven protected plants produced spontaneously 

 any capsules, and these it might have been thought 

 must have been self-fertilised. There were altogether 

 seven such capsules ; but as they were all seated close 

 to the artificially crossed flowers, I can hardly doubt 

 that a few grains of foreign pollen had accidentally 

 fallen on their stigmas. Besides the above seven 

 plants, four others were kept covered under the same 

 large net; and some of these produced here and 

 there in the most capricious manner little groups 

 of capsules ; and this makes me believe that a bee, 

 many of which settled on tho outside of the net, being 



Z 



