SCIENTIFIC COMMITTEE. 



XCV 



Scientific Committee, December 2, 1919. 



Present : Mr. E. A. Bowles, M.A., F.L.S., V.M.H. (in the Chair) ; Dr. A. B. 

 Rendie, Dr. W. Bateson, Messrs. J. Fraser, W. Hales, W. Fawcett, F. J. C. 

 Chittenden (hon. sec.), Messrs. Langley Smith and Crane, visitors. 



White-seeded Beans. — Dr. Rendie showed, on behalf of Mr. Spencer of Chob- 

 ham, a series of runner beans. A white-seeded form, and several varieties 

 between that and the ordinary black-and-purple form, had appeared some years 

 ago, and Mr. Spencer had selected each year the white form until now almost 

 all the plants gave white seeds only. The original culture had probably con- 

 tained a heterozygous plant, and possibly also crossing had occurred to a greater 

 or less extent each season with a purplish form. 



Hybrid Pelargoniums. — Mr. Langley Smith of Catford showed a series of 

 hybrid Pelargonium species with the object of illustrating inheritance of leaf- 

 cutting, purple- veining, variegation, etc., and a number of Antirrhinum seedlings 

 to illustrate the means of roguing, well known to many growers, in the seedling 

 state, where the colours of the under- epidermis are a guide as to the white, 

 coloured or streaked nature of the flowers. 



He sent the following notes with them : 



Variegation as a Heritable Character. 



X. Further Notes on the Inheritance of Variegation in Pelargoniums. A. P. 

 denticulatum X P . filicifolium (Sets A, B, and C, 5/1/16). 



Variegation has, in this instance, developed in the course of experiments in 

 hybridisation, and has definitely proved itself to be a heritable character. 



Of the samples of sets A, B and C, exhibited on 5/1/16 to the R.H.S. Scientific 

 Committee, the report says " The variegation was, as a rule, but poorly marked, 

 and in many took the form of a very narrow whitish line round the margin of 

 the leaf." 



Seedlings, F 8 Generation. 



F 2 Breeding Number Variegated Not Variegated 



Set A 14 5 6 



Set C 15 4 3 



Set B 16 1 6 



Set A 17 7 1 



Set B 18 5 3 



22 19 



Doubt has been thrown on the hardiness of these variegated seedlings as 

 compared with the non- variegated. 



During the spring of 191 9, very severe weather was experienced, and on 

 three successive nights 6 degrees of frost were registered in the greenhouse in 

 which the plants were. This proved fatal to many Zonales, all the Tomentosum 

 section, many of the Citriodora section, as well as P. diadematum, P. Vandesii, 

 P. Blandfordianum, P. capitatum, P. Radula, P. x ' Clorinda/ ' M. Nonin,' and 

 all the ' Show ' and ' Fancy ' varieties. 



Of the section exhibited, however, the following survived the ordeal : 



Breeding No. Variegated Not Variegated 



14 4 2 



15 2 3 



16 1 5 



17 5 1 



18 3 1 



B. Inheritance of dark veining : F r P. ' Cataract ' (P. Radula x P. denti- 

 culatum), no dark veining. F 2 . P. ' Cataract A ' (P. x ' Cataract ' x P. denti- 

 culatum seedling 2), dark veins. F 3 . 2 Seedlings (P. x ' Cataract A ' x P. 

 denticulatum seedling 2), one dark veins, one not. 



C. Inheritance of dark foliage: P. zonale 'Black Vesuvius' selfed.- 7 

 seedlings, 6 dark foliage, 1 green foliage ; 2 dark seedlings = ' Black Vesuvius ' ; 

 1 dark seedling, salmon flower ; green-leaf seedling, dark- red flower. 



