304 .1 BdrtirldJ Disra.^r of Turin'/) (Brassica Napus) 



PARAisiTisM. Produces a soft -rot in swede, potato, carrot, radish 

 and cabbage. No growth on beetroot. 



Ferments. Pectinase ; diastatic and peptonising ferments produced. 



Re.\ctiox of Bv-PROnrcTS. Diseased pulp neutral or feebly alkaline; 

 bouillon neutral; acid produced in sugar media: production of ammonia 

 in the vegetable media. COg evolved from diseased pulp. 



Reaction to Stains. Stains easily with various auilin dyes and by 

 Gram's method. With Loeffler's flagella stain, one pole hyaline. 



rONCLUSION. 



While tlie organism under consideration has many characters in 

 common with Pseudomonas campestris (Smith) and with Bacillus 

 Oleracea (Harrison) it is clearly most nearly related to Pseudomonas 

 destructans (Potter). The writer is of opinion that it is a varietal form 

 of the latter. Of the differences mentioned in the table the most striking 

 is the mode of attack of the disease while the root retains its shape, 

 with the rind firm and the mature foliage healthy. 



This investigation was carried out in the Laboratory of Agricultural 

 Botany, University College, Bangor. It was taken up at the instance 

 of Prof. J. Lloyd Williams (formerly Adviser at Bangor) who had ob- 

 served this disease on farms in North and South Carnarvonshire, but 

 his enquiries in the other Counties failed to bring to light any other 

 instances of its occurrence, although many cases were observed of other 

 rots of swede and turnip. To him the writer wishes to express great 

 indebtedness for guidance and kindly ad\'ice and also to Professor 

 R. G. White by whose courtesy he had access to the ].,aboratory and 

 the College Farm. 



LITERATURE. 



(1) Caeruthers and Smith. Journal of Botany, 39 (1901). 



(2) GnuNGHAM, C. T. Formation of Calcium Carbonate by bacteria in the soil. 



Journ. Agric. 8ci. 4. 



(3) Johnson and Adams. Bacterial Kot in Turnips and other Brassicas in Ireland. 



Economic Proc. of the Royal Dublin Society, 2, Xo. 1. 



(4) Potter, M. C. («) On a bacteiial disease of the Turnip (Br. Xapus). Proc. of 



Royal Hoc id y. 67. 



(b) On the parasiti^^m of Pseudontoiias deslructan.s. Proc. of 



Royal Society, 70. 



(c) A brief review of Bacteriological Research in Phytopathology. 



Science Progress, 5. 



(d) Bacterial diseases of Plants. Journ. of Agric. Sci. 4. 



(e) Brown Rot of Swedes. Journ. of Bd. of Agric. 10. 



( / ) On a method of checking Parasitic Diseases in Plants. 

 Journ. Agric. Sci. 3. 



