FUNCTION.] HYBRIDS BY CONFLUENCE. 245 



case, it is clear there could not have been the great dissimi- 

 larity which presented itself in these twin-plants the produce 

 of a single seed." (Annals of Natural History, i. n. s. 163.) 



This view of the essential phenomena of fertilisation 

 receives much apparent support from some singular cases of 

 quasi-hybrid plants, which do not appear to have been produced 

 from seed, but are believed to have sprung from the accidental 

 mixture or grafting of common cellular tissue. A Citrus, 

 which produces fruit whose rind is that of the orange in part 

 and of the lemon in part, is supposed to have had such an 

 origin : but the most singular example is to be found in a 

 plant called in the gardens Cytisus Adami, or the purple 

 hybrid Laburnum, whose flowers and leaves are sometimes 

 those of Cytisus Laburnum, sometimes of Cytisus purpureus, 

 and sometimes intermediate between the two. Dr. Herbert, 

 in his learned paper on hybrids, in the Journal of the Horti- 

 cultural Society, speaks of it thus : 



" In the garden of the late Mr. London, at Bayswater, upon 

 a large shrub of the same hybrid, one of the limbs resolved 

 itself into its elements, diverging into two branches, one of 

 which had the small weeping habit, leaves, and flowers of 

 C. purpureus, the other nearly the leaves and racemes of 

 yellow flowers belonging to the common laburnum ; and 

 those two branches ripened good seed, whilst the rest of 

 the shrub producing the hybrid blossom was absolutely sterile. 

 The seeds borne by the smaller branch were less abundant 

 and had been lost ; those on the yellow branch were plentiful, 

 and I raised many plants from the seeds, which were kindly 

 given to me by Mr. London. They returned nearly to the 

 form of the common laburnum, excepting that two of the 

 seedlings showed a little purple tinge on the green stalks, 

 which might, perhaps, have extended to the flowers, but they 

 were lost by neglect. In the same season the diminutive 

 branch on my brother's tree bore seed, and from it I raised 

 plants, differing very little from the usual C. purpureus. The 

 history of the plant is, that it was not raised from seed, but 

 made its appearance in the following remarkable way : A 

 number of stocks of laburnum had been budded with C. 

 purpureus in a French nursery-garden, and the bud on one 



