4 OBSEEVATlOJfS UPON MULING AMONG PLANTS. 



place between two pure species, it is an universal rule, " that the 

 cliaracfers of tlie parents never remain pure and unaltered in the 

 fortiiation of the hybrid." In general every part of the new pro- 

 duction is modified, so that it presents a decided diflerence fiom 

 either of the parents, though resembling the one more tlian the 

 otiier. In no case, however, are anomalous forms generated 

 bearing no resemblance to either. At the same time they are 

 not produced according to mathematical formulse and ratios ; 

 tlieir differences are mingled in unequal proportions, and may be 

 arranged under three heads, viz. intermediatCj mixed, and de- 

 cided hybiids, of which mention will be made presently. And 

 it is to be observed, that the change does not always take place 

 in the whole of the plant, as though the principle on which it 

 depends penetrated into the intimate structure of the whole 

 plant ; but even in the most decided hybrid types, as Nicoliana 

 paniciilato-vinccpJio7-a, and vincajioro-LangsdorJii^ as well as in 

 the mixed forms, particular organs undergo only a very slight 

 modification, while others are materially changed. 



It was remarked, that no instance has occurred in which the 

 characters of the parent remain perfectly unaltered in the 

 hybrid. An apparent exception, however, to this rule requires 

 notice. In 1846 Lychnis Jios-cuculi was treated with the pollen 

 of Cucuhalus Behen. Amongst many normal plants of the 

 former, a single example occurred, which differed as to habit 

 and blossoms not the least from the female parent, but the leaves 

 in form and in their glaucous appearance, especially the root- 

 leaves, agreed completely with those of the male. Repeated 

 attempts to reproduce this form were unsuccessful. The author, 

 however, does not regard the partial alteration of form and sub- 

 stance of the leaves as the effect of the strange pollen ; but 

 believes that all the plants produced arose from an impregnation 

 of the Lychnis with its own pollen after the attempted hybridiza- 

 tion with that of the Cucuhalus, especially since all of them, whe- 

 ther normal or exceptional, were as fruitful as the motlier-plant. 



In Nicotiana suaveolenti- Langsdorjii and vinc(pJioro-Langs- 

 dorfii the change is very slight, consisting merely in a trifling 

 alteration of colour in the blossoms, in the violet or blue colour 

 of the anthers, and in a partial separation of the stamens from 

 the tube of the corolla : in other respects the resemblance to the 

 female parent is very close, insomuch that doubts as to their 

 being really hybrids might be entertained, were they not com- 

 pletely barren. Unfortunately it is impossible to reverse the 

 experiment in these cases, as iV. Langsdorjii is not fertile except 

 when impregnated with its own pollen. 



Various notions have existed, both in the animal and vegetable 

 kingdom, with respect to the degree of influence which the sexes 

 have in the production of hybrids : according to one authority, 



