XXxii PROCEEDINGS OF THE ROYAL HORTICULTURAL SOCIETY. 



SCIENTIFIC COMMITTEE. 



January 14, 1902. 

 Dr. M. C. Cooke in the Chair, and thirteen members present. 



Cyclamen Diseased. — Mr. A. J. Reid sent corms, the roots of which 

 were clubbed, as happens in Cabbages. On examination the appearances 

 w r ere seen to be due to the presence of nematode worms (eel- worms). 



Pelargonium Leaves. — From Mr. G. W. Murtrie came leaves of 

 Pelargonium in various stages of decay. Dr. Cooke carefully examined 

 the leaves, and reports :— 



" The leaves of Pelargonium were disfigured by large brown indeter- 

 minate blotches of dead tissue, which did not reveal any fungus mycelium 

 when submitted to the microscope, and there was nothing local to account 

 for the spotting. The whole appearance suggested at once to members 

 of the Committee practically acquainted with Pelargonium culture that 

 the appearances were of the same character as are known to be caused 

 by sour soil, and that the only remedy was to transplant into fresh soil 

 at once. After twenty-four hours, the dead parts produced a plentiful 

 crop of the common blue mould (Penicillium glaucum), which is a 

 ' saprophyte,' and only occurs on dead matter as a consequence of decay, 

 but is never itself productive of disease." 



Arum Corms. — Some corms of Bichardia africana were shown, with 

 here and there a patch of decayed tissue like a bruise. Dr. Cooke 

 examined the specimens and reported : — 



" Both corms, otherwise of a healthy appearance, exhibited on one 

 side an orbicular brown diseased spot, about \ inch in diameter, 

 entering the corm to nearly the same depth, surrounded by a paler ring 

 exhibiting the spreading of the spot. The decayed matter from the spot 

 showed no trace of mycelium, but was almost entirely composed of 

 elliptical colonies of nearly globose hyaline bodies, about three to four 

 micromillimetres in diameter, reminding one of the colonies found in 

 Lamprocystis. I am therefore inclined to the belief that the disease is 

 some obscure form of bacteriosis, hitherto undescribed." 



Iris unguicularis. — Mr. Bowles showed a ripe capsule of this species, 

 Avhich only occasionally ripens its seed-vessels. 



Scientific Committee, January 28, 1902. 



Mr. H. J. Veitch in the Chair, and twelve members present. 



Bichardia and Cyclamen Corms. — Mr. G. S. Saunders reported on the 

 corms sent to the last meeting : " The Richardia corms are attacked by 

 one of the 1 bulb mites,' probably Bhizoglyphus cchinojms ; it is a very 

 difficult pest to deal with. Water at a temperature of 115° Fahr. will kill 

 them. I should add 4 oz. of sulphide of potassium to every quart of water, 

 and allow the corms to remain in the mixture for ten minutes or a quarter 



