318 THE PHENOMENON OF 



Strasburg, Schiltigheim, Munich, Vienna, Carlsrulie, 

 Freiburg (and England), that single shoots present them- 

 selves upon the stocks of C. Adami, which (without any 

 mediating transitions)* represent quite purely the yellow- 

 flowered and villous C. Laburnum, or, what is much more 

 striking from the great difference of the habit, branches 

 perfectly characterised as C. purpureus. Ordinarily only 

 one or other of the two parent species appear in this 

 way,t but sometimes both on the same stock-l The 

 formation of sprouts, and indeed the formation of twig- 

 buds, is consequently the turning point here, with which 

 the recurrence of the hybrid into the parent-species 

 occurs; the recurring buds develope into stronger or 

 weaker twigs, which in all parts belong entirely to one 

 or other parent-species (stem-, leaf-, flower-, and fruit- 

 formation). Sometimes, however, the case occurs of the 

 recurrence to the parent-species first in the small twigs 

 of the inflorescence, i. e. in the transition to the single 

 lateral buds of the raceme, whereby the flowers belonging 

 to the parent-species originate in the inflorescence of the 

 hybrids and mixed racemes are formed. Three kinds of 

 these are possible, namely : 1, C. Adami mixed with 



* KiroUeger says, indeed, — " J'ai pu meme, en 1844, observer toutes les 

 transitions de ces trois sortes de braneiies (aveo leurs inflorescences et leurs 

 flenrs) les unes aux autres," but this assertion is certainly incorrect. 

 Kirschleger was certainly deceived by the mixed inflorescences and flowers, 

 which I shall describe more minutely. 



f I have observed tljis in Carlsruhe and Freiburg, where I never saw 

 both parent species produced out of the same stock. Buchinger found the 

 same. I mention this circumstance expressly in order to remark that the 

 explanation given by Chevreul, (1. c.) by wliich the recurrence of C. Adami 

 to its parent species as a decomposition of the hybrid into its two portions 

 (somewhat as in a chemical decomposition) is inapt. 



X This is expressly asserted of the tree occurring in the garden of Prof. 

 Schweighauser, at Schiltigheim, which was described by Kirschleger. (This 

 occurred also in the specimen in the garden of L.W. Dillwyn, Esq., of Swan- 

 sea, where the shoots bearing the blossoms of the parent species were fertile, 

 ripening seed, while the hybrid blossoms were sterile as usual. — A. H.) 

 Since it is probable that all the specimens of C. Adami diffused in gardens 

 are cuttings of a single mother-stock, the distinction, whether only one or 

 both parent-species present themselves, becomes of less importance. 



