154 ARTIFICIAL FERTILISATION 



seed be there. 4th, Seeds are present, but small, languid, and 

 incapable of germination. 5th, Seeds apparently perfect are 

 developed which do not germinate. 6th, Seeds which ger- 

 minate, but the young plants are weak, and wither in a short 

 time, dying off oftentimes after developing the seed-leaves. I 

 have had all these conditions and results amply illustrated ; and 

 of the second of these results I had, last summer, mortifying 

 proofs in a muling operation I tried, by fertilising a flower of 

 the new Arabis blepharophylla with my still newer Draba 

 violacca. The cross, to all appearance, had taken ; the seed- 

 vessel swelled better than the others where no experiment was 

 made, and while the valves of the silicules of these last opened, 

 and showed no trace of seed in them, the siliquas of the former 

 remained closed, showing by outward development that two 

 seeds were certainly within. But I found on opening the ripe 

 seed-vessels that there was no perfect seed in the interior, but 

 only an abortive production. While Wichura's accuracy in the 

 above degrees of failure is consistent with what I have myself 

 had ample experience of, I cannot, from like experience, endorse 

 the views he has formed on some of his successful results. At 

 page 72 of the above article in the 'Journal of the Royal 

 Horticultural Society,' Mr Berkeley, commenting on Wichura's 

 paper, observes : " Gaertner, indeed, supposes that in genera 

 which are rich in species, there are some which have a pre- 

 potent influence when hybridising, so that in some hybrids the 

 type either of the male or female prevails. Amongst the 

 various hybrid Willows, though the genus is so rich in species, 

 and so prone to hybridising, Wichura has never seen a pre- 

 potent type, and doubts Gaertner's statement, especially as 

 he makes it in very qualified terms." Mr Berkeley very judi- 

 ciously remarks that it is not very easy to determine, "by 

 examination of types, whether a hybrid is more like the mother 

 or father the perfect distinction is subject in many cases to 

 great difficulties, since very much depends on the subjective 

 view of the observation ; for, in consequence of the frequent 

 intermelting of both characters, the one observer finds in a 

 hybrid the maternal type, while another thinks the paternal 

 type prevalent." By which I regard Mr Berkeley as very 

 modestly dissenting from his author. And further on, at page 

 78 of the same Journal, Wichura speaks out still more 

 absolutely. "When both parents," says he, "belong to the 

 same species, we cannot tell what part the male and female 

 parent take respectively in the formation of the progeny. But 

 dissimilar factors are united in hybrids, and an intermediate 

 form is the consequence. The products which arise from 



