530 JOURNAL OF THE ROYAL HORTiCUL'rURAL SOCIETY. 



with Horne) that Berkeley's figure is somewhat incorrect, and that 

 his description is meagre; and further that the identity of Berkeley's 

 organism with the modern Spongospora rests on the results of John- 

 son's microscopical examination of Berkeley's type material much 

 more securely than upon the latter's description and figure. I think 

 everyone who has seen them will agree that the figure and descriptions 

 published by Martius and by Wallroth lend themselves with a far 

 greater degTee of certainty to the identification of the organism than 

 is the case with those of Berkeley, and it seems clear that Mas see 

 cannot have been well acquainted with them. 



Finally, a word as to the trivial name for this disease. In my | 

 opinion as much care should be taken to avoid multiplying trivial names ! 

 for diseases as should be devoted to ascertaining the strict scientific 

 names of the parasites causing them. The trivial names are presum- 

 ably for the use of the gardener and farmer (and on non-state occasions 

 for the less pedantic pathologists!), and it is rather a hardship to 

 inflict on them a long list of names for one and the same disease. 

 " Corky-End," Oorky-Scab," and " Powdery-Scab " are names 

 which, have already been given to this particular disease, and Horne j 

 now adds another one — viz. " Potato-canker " — although, as he him- 

 self points out, this is one of the names under which the Wart Disease 

 is also known. The onus of having invented the name potato- \ 

 canker is thrown on the present writer's shoulders, but although I was 

 perhaps the first to point out that not infrequently the scabs produced 

 by the organism were so extensive that they merited the term canker 

 rather than scab, I had no intention whatever of suggesting another 

 trivial name for the disease. The spot or simple scab form of the 

 disease is, in my experience, far more common than the canker form, 

 and the term potato-canker for this form of it is, in my opinion, most 

 inappropriate. In the case of many of the really deeply cankered 

 tubers which I have examined, Spongospora has been associated with 

 other organisms, both animal and vegetable, and it has yet to be deter- | 

 mined to what extent, if any, the decay of the tissues of the tubers is 

 due to these other organisms. Hence I consider the addition of the 

 further trivial name, potato-canker, for this disease to be quite un- 

 necessary. 



