444 



JOUENAL OF THE ROYAL HORTICULTURAL SOCIETY. 



Discussion. 



Mr. EoLFE said it would be interesting and valuable if something 

 reliable could be ascertained about the subject of albinism. Albinism 

 was a quality — a very beautiful quality — and no doubt it arose from the 

 absence of colour, but there was the difficulty that some albinos repro- 

 duced themselves true when selfed and yet reverted to coloured forms 

 when crossed. Both Cattleya Warneri alha and C. Gaskelliana alha 

 were true albinos, as far as could be ascertained by examining the 

 flowers, but when crossed together some of the resulting seedlings 

 were pure white and others light rose, showing that a latent colour 

 factor had been revived. In the case of C. intermedia x C. Mossiae 

 Wageneri, however, the whole batch (0. x Dusseldorfei ' Undine ') was 

 white. Cypripedium insigne Sanderae, when crossed with C. callosum 

 Sanderae or G. Lawrenceanum Hyeanum, gave rise to coloured hybrids, 

 yet all three came true when selfed. C. insigne Sanderae, however, 

 though one of the best yellows, was not a true albino, for it showed 

 minute brown spots on the dorsal sepal, and the effect of crossing was 

 to stimulate their development in the hybrids, the effect being much 

 the same as if ordinary coloured forms of C. insigne were used. The 

 effect of crossing was to revive a latent factor, and of course when 

 plants were selfed no new and disturbing element was introduced. 

 But even when plants were selfed, the offspring were not always 

 uniform. Messrs. Veitch had raised a batch of C. insigne Sanderae 

 by self-pollination, and though all came yellow, they were not uniform 

 in character. Flowers of five seedlings had been picked out and sent , 

 to him no two of which were alike, and in one the spots were distinctly 

 more marked than in the original, while another was pure yellow, as 

 pure as C. insigne ' Gladys, ' and he could not detect a speck of brown ! 

 or a coloured hair anywhere. Eeversion as the result of crossing was 

 not remarkable, for lost or latent characters mxight easily be revived. A j 

 plant might be regarded as made up of a host of characters which had 

 been successively acquired, and some of these were evidently very 

 ancient, while others were more recent. In the course of evolu- ! 

 tion new characters were constantly arising. In conclusion, he appealed | 

 to all those who were making experiments to send the results to the 

 Press, as by so doing a mass of evidence would be accumulated that 

 would be of the greatest value to orchidists. 



Mr. Fraser said he had not given much attention to albinism in 

 Orchids, but thought it was not always possible to get seedlings with 

 pure white flowers, although both parents were albinos. It was 

 frequently, if not always, impossible to tell what characters were latent 

 in an albino till one commenced cross-breeding or hybridizing with it. 

 He had collected many albinos of native wild plants, and, judging by 

 the first white-flowered Campanula rotundifolia he had gathered, he 

 contracted the notion that albinos must be more delicate than the type, 

 owing to the loss of some character. There was a correlation between 

 the colour of the flowers and all other parts of the plant, which were 



