THE THEEE F0EM3 OF XTTHBrjI SALICAHIA, 187 



the eighteen possible vinions the polleu-tubes penetrated, after 

 eighteen hours, the stigma. I have reason to believe that the 

 ofispring from the illegitimate unions present some singular 

 characteristics ; but until my observations on this head are re- 

 peated, I must be silent. At first I thought that perhaps two 

 kinds of pollen placed together on the same stigma would give 

 more fertility than any one kind ; but we have seen that this is 

 not the case with each form's own two kinds of pollen ; nor is it 

 probable in any case, as I occasionally got, by the use of single 

 kinds of pollen, fully as many seed as I have seen in a capsule 

 naturally fertilized. Moreover the proper pollen from a single 

 anther is more tlian sufficient to fully fertilize each stigma ; hence, 

 in this as in so many other cases, at least twelve times as much 

 of each kind of pollen is produced as is necessary to ensure full 

 fertilization. From the dusted condition of the whole body of 

 those bees which I caught on these flowers, it is probable that 

 some pollen of all kinds is deposited on each stigma ; but there 

 can hardly be a doubt that the pollen of the stamens of corre- 

 sponding length will be prepotent and will wholly obliterate any 

 eft'cct from tho other kinds of pollen, even if previously deposited 

 on the stigma. I infer this partly from the fact ascertained by 

 Glirtner tliat each species' own pollen is so prepotent over that of 

 any other species, that if put on the stigma many hours subse- 

 quently, it will entirely obliterate the action of the foreign pollen. 

 But I draw the above inference especially from the following 

 experiment : I fertilized homomorphically or illegitimately some 

 long-styled Cowslip flowers (^Primula veris) with their own pollen, 

 and exactly twenty-four hours subsequently I fertilized these 

 same stigmas heteromorphically or legitimately with pollen from 

 a short-styled dark-red Polyanthus. I must premise that I have 

 raised many seedlings from crossed Cowslips and Polyanthus, and 

 know their peculiar appearance ; and I further know, by the test 

 of the fertility of the mongrels inter se, and with both parent 

 forms, that the Polyanthus is a variety of the Cowslip, and not of 

 the Primrose (P. vulgaris) as some authors have supposed. iS^ow 

 from the long-styled Cowslip twice fertilized in the manner ex- 

 plained, I raised twenty-nine seedlings, and every one of them 

 had flowers coloured more or less red ; so that the heteromorphic 

 Polyanthus-pollen wholly obliterated the influence of the homo- 

 morphic pure Cowslip-pollen, which bad been placed on the 

 stigmas twenty-four hours previously, and not a single pure 

 Cowslip was produced. 



