CXxii PROCEEDINGS OF THE ROYAL HORTICULTURAL SOCIETY. 



in this and in several similar cases that have recently come to notice 

 this cause cannot have been acting. 



Crown Gall. — Mr. H. T. Gussow sent a culture of the Bacterium 

 tumejaciens which Dr. Erwin Smith has shown to be the cause of 

 the disease known as crown gall. This disease attacks numerous 

 plants, producing large swellings, generally of a soft nature, on the 

 roots and lower parts of the stems, and in America it is frequently 

 credited with doing damage to the plants attacked. The Committee 

 would be glad to learn whether any serious results have followed 

 the occurrence of such swellings on the roots of plants. Instances 

 have been brought to the notice of the Committee of swellings on 

 Apple, Plum, Birch, Cherry, Peach, Carnation, Marguerite, Blackberry, 

 Loganberry, and Cupressus. 



Scientific Committee, August 26, 1913. 



Mr. E. A. Bowles, M.A., F.L.S., F.E.S., in the Chair, and seven 

 members present. 



Mr. Chittenden reported that the Violet leaves sent by Mr. Druery 

 were attacked by the gall midge, Cecidomyia violae. 



Double Gladioli. — A letter from Col. Sandeman was read in 

 connexion with the alleged doubling of Gladioli. As no specimen 

 came with the letter, the Committee could not decide the point raised. 

 Incidentally, Dr. Bateson remarked that if the fact were established 

 it would be interesting, as there were several families or orders, such, 

 for example, as the Labiatae, that, although having peloric forms, do 

 not show true doubling of the flower. 



Campanula Disease. — Mr. Edwards, of Sylfaen Gardens, Welshpool, 

 sent leaves of Campanula persicijolia affected with Puccinia Campanulae 

 (Plowright and Berkeley). 



Late Brood oj Sawfly. — Mr. Edwards also sent a brood of the 

 Sawfly (Gooseberry) caterpillar, Nematus ribesii. The Committee 

 thought this should be recorded owing to the very late period of 

 hatching. 



Matricaria suaveolens = M. discoidea. — Mr. Odell showed this 

 little Composite from N.-W. Middlesex. It is a recent immigrant 

 to this country, and has been recorded by Mr. E. Bowles from Essex 

 and Hertfordshire, and by Mr. J . Fraser from Aberdeen. 



Fasciated Aloysia citriodora. — Mr. Odell showed stems of this 

 plant fasciated, and having a very mixed phyllotaxis, with the 

 terminal parts showing the normal terete stem and normal phyllo- 

 taxis. Dr. Bateson remarked that the condition was similar to that 

 of the Crown Pea, Pisum umbellatum, where from a densely fasciated 

 stem normal shoots were developed with flowers. 



