APPENDIX 341 



to those of Ph. multiflorus, while the ground colour was not ma- 

 terially different. The next year forty-four plants were raised 

 from these seeds, of which only thirty-one reached the flowering 

 stage. The characters of Ph. nanus, which had been altogether 

 latent in the hybrids, reappeared in various combinations; their 

 ratio, however, with relation to the dominant plants was neces- 

 sarily very fluctuating owing to the small number of trial plants. 

 With certain characters, as in those of the axis and the form of pod 

 it w^as, however, as in the case of Pisum, almost exactly 1 :3. 



Insignificant as the results of this experiment may be as regards 

 the determination of the relative numbers in which the various 

 forms appeared, it presents, on the other hand, the phenomenon of 

 a remarkable change of colour in the flowers and seed of the hybrids. 

 In Pisum it is known that the characters of the flower- and seed- 

 colour present themselves unchanged in the first and further 

 generations, and that the offspring of the hybrids display exclu- 

 sively the one or the other of the characters of the original stocks. 

 It is otherwise in the experiment we are considering. The white 

 flowers and the seed-colour of Ph. namis appeared, it is true, at 

 once in the first generation [from the hybrids] in one fairly fertile 

 example, but the remaining thirty plants developed flower-colours 

 which were of various grades of purple-red to pale violet. The 

 colouring of the seed-coat was no less varied than that of the 

 flowers. No plant could rank as fully fertile; many produced no 

 fruit at all; others only yielded fruits from the flowers last pro- 

 duced, which did not ripen. From fifteen plants only were well- 

 developed seeds obtained. The greatest disposition to infertility 

 was seen in the forms with preponderantly red flowers, since out of 

 sixteen of these only four yielded ripe seed. Three of these had a 

 similar seed pattern to Ph. multiflorus, but with a more or less pale 

 ground colour; the fourth plant yielded only one seed of plain 

 brown tint. The forms with preponderantly violet-coloured 

 flowers had dark browTi, black-brown, and quite black seeds. 



The experiment was continued through two more generations 

 under similar unfavorable circumstances, since even among the 

 offspring of fairly fertile plants there came again some which were 

 less fertile or even quite sterile. Other flower- and seed-colours 

 than those cited did not subsequently present themselves. The 

 forms which in the first generation [bred from the hybrids] con- 

 tained one or more of the recessive characters remained, as regards 



