72 Jrn. bvrwis o>' titt; existexoe of two ronjts 



the st<atcment tliat the two forms are produced iu about equnl 

 numbers. The fivst thirty-four plauts were kept under a net 

 which excluded insects. I fertiUzed heteromorphically fourteen 

 long-stylod flowers with pollen from the short-styled, and got 

 eleven fine seed-capsules ; these contained on an average 8-6 seeds 

 per capsule, hut only 5-6 were apparently good. It may be well to 

 state tliat ten seeds is the maximum possible production for a 

 capsule, and that our climate cannot bo very favourable to this 

 North-African plant. On three occasions I fertilized homomor- 

 phically the stigmas of altogether nearly a hundred flowers (but 

 did not separately mark them) with their own pollen, but taken 

 from separate plants, so as to prevent any possible ill effects 

 from close interbreeding ; and many other flowers were produced, 

 which, as before stated, would get plenty of their own individual 

 pollen ; yet from all these flowers, borne by the seventeen long- 

 styled plants, only three capsules were produced; one of these iu- 

 cluded no seed, and the other two together gave only Ave good 

 seeds. Kor do I feel at all sure that this miserable product of the 

 two half-fertile capsules from the seventeen plants, each of which 

 must have produced at least fifty or sixty flowers, is really the re- 

 sult of their fertilization by their own pollen ; for I made a great 

 mistake in keeping the two forms under the same net, with their 

 branches often interlocking, and it is surprising that a greater 

 number of flowers were not accidentally fertilized. 



Of tlie short-styled flowers I fertilized heteromorphically twelve 

 witli the pollen of tlie long-styled (and to make sure of the result 

 I previously castrated the majority), and obtained seven fine seed- 

 capsules. Tliese included an average of 7'6 seeds, but of apparently 

 good seed only 4'3 per capsule. At three separate times I ferti- 

 lized homomorphically nearly a hundred flowers with their own- 

 form pollen, taken from separate plants ; and numerous other 

 flowers were produced, many of which must have received their 

 own pollen. From all these flowers borne on the seventeen plants, 

 only fifteen capsules were produced, of which only eleven con- 

 tained any good seed, on an average 4-2 per capsule. xA^s remarked 

 in the case of the long-styled plants, some even of these capsules 

 were perhaps the product of a little pollen accidentally fallen 

 from the flowers of the other form. Nevertheless the short- 

 styled plants seem to be slightly more fertile with their own 

 pollen, in the proportion of fifteen capsules to three, than the 

 long-styled : the real proportional excess in fertility is probably 

 a little greater, as the short-styled flowers, when not disturbed, do 



