CCXX PEOCEEDINGS OF THE ROYAL HORTICITLTURAL SOCIETY. 



however, a complete series of stages has been obtained between streaked 

 and rotten tubers of the same variety of potato. The following stages 

 in the development of streak disease in the variety ' Duke of York ' 

 were sent for inspection : — 



1. Potatos marked internally with streak's as described in the 

 Journal of Agrimilhiral Science, iii, September, 1910. 



2. Potatos with internal brown rot. Upon closely inspecting the 

 flesh the rotten area is seen to be made up of a number of concentric 

 curved brown lines; the lines are very numerous, and almost in 

 contact with one another. The lines show up well when a slice of 

 the potato is soaked in potash. 



3. Potatos with cavities in the flesh which are bounded by a brown 

 zone of diseased tissue. 



4. Potatos similarly diseased, but having external injuries. 



The diseased potatos were raised in Scotland, with the co-operation 

 of Mr. W. G. McGowan, in connexion with potato investigations, of 

 which an account has not yet been published. The seed potatos of 

 the variety * Duke of York ' were obtained from a locality in which 

 streak disease is at present unknown, and were free from disease when 

 planted. 



Scientific Committee, December 5, 1911. 



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



members present. 



The late Mr. James Douglas, V.M.H. — It was unanimously resolved 

 to convey a vote of condolence to Mrs. Douglas on the death of Mr. 

 James Douglas, who had for many years been a member of the 

 Scientific Committee. 



Double Odontoglossum crispum. — Mr. Gurney Wilson, on behalf of 

 Mr. Jensen, showed a double flower of Odontoglossum crispum. The 

 two outer whorls were normal, but the stamens had apparently 

 developed and become petaloid. The plant showed the same peculiarity 

 each year. 



Gall on Ribes alpinum. — Dr. Pendle, F.E.S., exhibited a branch of 

 Ribes alpinum from a place near Grantham, having large numbers of 

 black galls upon it about f inch to 1 inch long, so numerous that the 

 whole bore a superficial resemblance to a small branch of larch bear- 

 ing numerous small cones. The cause oT the production of these galls 

 was unknown. 



Uncommon fruit. — Mr. Gordon, Y.M.H., exhibited a ripe fruit of 

 Holboellia latifolia {Stauntonia latifolia) from a wall at Somerleyton 

 Hall, where it had not been known to fruit before. 



Aberrations of Saxifraga ligulata. — Mr. ^Yorsdell, F.L.S., showed 

 specimens of leaves from a plant of Saxifraga ligulata at Kew which, 

 season after season in the autumn, produces leaves of ascidia form 

 and developed in different degrees. Man}" of the leaves showed cresting 

 as well. 



