8 



JOUENAL OF THE EOYAL HOETICCLTUEAL SOCIETY. 



because the characters thereby designated withdraw or entirely disappear 

 in the hybrids, but nevertheless reappear unchanged in their progeny, a& 

 will be demonstrated later on. 



It was furthermore shown by the whole of the experiments that it is 

 perfectly immaterial whether the dominant character belong to the seed- 

 bearer or to the pollen f)arent ; the form of the hybrid remains identical 

 in both cases. This interesting fact was also emphasised by Gartner, 

 with the remark that even the most practised expert is not in a position 

 to determine in a hybrid which of the two parental species was the seed 

 or the pollen plant. 



Of the differentiating characters which were used in the experiments 

 the following are dominant : — 



1. The round or roundish form of the seed with or without shallow 

 depressions. 



2. The yellow colouring of the seed albumen [cotyledons]. 



3. The grey, grey-brown, or leather-brown colour of the seed-coat, in 

 connection with violet-red blossoms and reddish spots in the leaf axils. 



4. The simply inflated form of the pod. 



5. The green colouring of the unripe pod in connection with the same 

 colour in the stems, the leaf- veins and the calyx. 



6. The distribution of the flowers along the stem. 



7. The greater length of stem. 



With regard to this last character it must be stated that the longer of 

 the two parental stems is usually exceeded by the hybrid, which is possibly 

 only attributable to the greater luxuriance which appears in all parts of plants 

 when stems of very different length are crossed. Thus, for instance, in 

 repeated experiments, stems of 1 ft. and 6 ft. in length yielded without 

 exception hybrids which varied in length between 6 ft. and 7| ft. 



The seeds of hybrids in the experiments with seed-coat are often more 

 spotted, and the spots sometimes coalesce into small bluish-violet patches. 

 The spotting also frequently appears even when it is absent as a parental 

 character. 



The hybrid forms of the seed- shape and of the albumen are developed 

 immediately after the artificial fertilisation by the mere influence of the 

 foreign pollen. They can, therefore, be observed even in the first trial 

 year, whilst all the other characters naturally only appear in the following 

 year in such plants as have been raised from the crossed seed. 



The Fiest Gexeeation from the Hybrids. 



In this generation there reappear, together with the dominant 

 characters, also the recessive ones with their full peculiarities, and this 

 occurs in the definitely expressed average proportion of three to one, so 

 that among each four plants of this generation three receive the dominant 

 character and one the recessive. This relates without exception to all the 

 characters which were embraced in the trials. The angular TVTinkled 

 form of the seed, the green colour of the albumen, the white colour of the 

 seed-coats and the flowers, the constrictions of the pods, the yellow colour 

 of the unripe pod, of the stalk, the calyx, and the leaf venation, the 

 umbel-like form of the inflorescence, and the dwarfed stem, all reappear in 



