76 MB. DAEWIN OH TUE EXISTENCE OF TWO rOEMS 



soon, I did not transplant them, and they -unfortunately grew with 

 their branches closely interlocked. All the plants were covered 

 by a net, excepting one of each form. First, of the long-st^ded 

 flowers, twelve were homomorphicaUy fertilized by their own-form 

 pollen, taken in every case from a separate plant ; and not one 

 flower set a seed-capsule : twelve other flowers were heteromor- 

 phicaUy fertilized by pollen from short-styled flowers ; and they set 

 nine pods, each including on an average seven good seeds : as 

 before, ten seeds is the maximum possible production. Secondly, 

 of the short-styled flowers, twelve were homomorphicaUy fertilized 

 by own-form pollen, and they yielded one capsule, including only 

 three good seeds ; twelve other flowers were hoteromorphically 

 fertilized by pollen of long-styled flowers, and these produced nine 

 capsules, hut one was bad ; the eight good capsules contained on 

 an average exactly eight good seeds each. 



The many flowers on the eleven long-styled plants under the 

 net, which were not fertilized, produced only three capsules 

 (including 8, 4, and 1 good seeds) ; whetlier, owing to the inter- 

 locking of the branches, these accidentally received pollen from 

 the other form, I will not pretend to conjecture. The single long- 

 styled plant which was uncovered, and grew close by the uncovered 

 short-styled plant, produced five good pods ; but it was a very poor 

 and small plant. 



The flowers borne on the thirteen short-styled plants under the 

 net, which were not fertilized, produced twelve capsules (containing 

 5'6 seeds on average) : as some of these capsules were very fine, and 

 five wore borne on one twig, I suspect tliat they had been visited 

 by some minute insect which had accidentally got under the net 

 and had carried pollen from the other form. The one uncovered 

 short-styled plant yielded exactly the same number of capsules, 

 namely, twelve. 



Prom these facts we have some evidence, as in the case of L. 

 grand iflwmn, that the short-styled plants are in a very slight 

 degree more fertile with their own pollen than are the long-styled 

 plants. And we have the clearest evidence, from the result of the 

 forty-eight flowers artificially fertilized, that the stigmas of each 

 form require pollen from the stamens of corresponding height 

 produced by the opposite form. 



In contrast with the case of L.grandiflormn, it is a singular fact 

 that the pollen-grains of both forms of X. perenne when placed on 

 their own-form stigmas, though not causing fertility, yet emit their 

 tubes; and these tubes I found, after an interval of eighteen 



