No. G. 



British Association — Potatoe Disease. 



189 



British Association.— Potatoe Disease. 



June 28tli — Mr. Westwood made some 

 remarks before the British Association, on 

 the e.xistence of the potatoe disease in Ox- 

 fordshire. Some potatoes of his own had 

 been attacked this year, and in three differ- 

 ent districts aronnd Oxford he had observed 

 its presence* As an entomologist, he wished 

 to deny most distinctly, that he thought the 

 disease arose from the attacks of an insect 

 It had been stated by Mr. Smee that it arose 

 from the attacks of a new aphis, which he 

 called vastator, but this aphis, far from being 

 new, had been described many years ago, 

 and was a very common insect on decaying 

 plants. Another gentleman proposed to call 

 the insect A. pestilens. Mr. Westwood 

 drew attention to the ignorance such ob- 

 servers dis[llayed, as rendering it necessary 

 that zoology should be taught as a branch of 

 education. He was sorry to be speaking on 

 this subject in an English University, where 

 neither zoology nor comparative anatomy 

 were recognised as necessary to complete 

 the education of the professional man or 

 gentleman. Mr. J. E. Gray stated, that he 

 had compared some specimens of the aphis 

 vastator with species of aphides in the Brit- 

 ish Museum, and found that under this name 

 Mr. Smee had included three or four well 

 known species. Dr. Lankester, drew atten- 

 tion to a bundle of potatoe stalks which he 

 had brought from Pangbourne, which gave 

 every sign of disease, but not an aphis could 

 be found among them. One fact of this 

 kind was sufficient to prove that the disease 

 had no dependance upon the insect. He 

 had heard from a gentleman in Manchester 

 that potatoes sown in new soil on Chat Moss 

 were free from the disease, whilst those 

 sown in old soil all had the disease. This 

 looked as if the inorganic constituents of 

 the soil or potatoe were the source of the 

 disease. Mr. Babington referred to the po- 

 tatoe stems from Pangbourne. He had ex- 

 amined the roots of these plants, and found 

 that wherever the disease appeared in the 

 leaves there was evidence of disease in the 

 roots. He believed the root or haulm was 

 first at fault. He quite agreed with Mr. 

 Westwood in the necessity of a more gene- 

 ral knowledge of natural history. Sir W. 

 Jardine said that chemical investigations of 

 a very accurate nature, both of the soil and 

 the potatoe, were being carried on in Edin- 

 burgh. He had found that potatoes grown 

 on moss soil were more free from disease 

 than others. This did not arise from the 

 newness of the soil, for he had had some po- 

 tatoes entirely spoiled which were planted in 

 an orchard recently turned up. He had 



seen the stem and root very much affected 

 without the leaves being diseased at all. 

 He was happy to say that in Edinburgh all 

 students of the University were expected to 

 attend the natural history lectures. Mr. 

 Hogan called attention to a method he had 

 pursued of preventing the disease in the po- 

 tatoe by growing them from seed. Mr. C. 

 Darwin had brought the seed of the potatoe 

 from Peru, and the tubers grown from it 

 were quite as much affected as any other. 

 Dr. Kelart stated that he had recently heard 

 from Ceylon that the potatoes had been at- 

 tacked in that island. A member said that 

 he had just received letters from New Zeal- 

 and, and the potatoe was also affected there. 

 The Rev. N. Young, of New College, ex- 

 hibited some potatoe leaves affected by the 

 aphis. 



On the Vitality of potatoe seeds, by John 

 D. Murray, Esq., of Murraythwaite. In 

 1832 or 1833, a portion of ground in my 

 garden, which produced a crop of potatoes, 

 was trenched to the depth »of 18 inches, and 

 after bearing various crops for several years 

 after, was turned into a flower garden, and 

 covered with turf, which was kept regularly 

 mown. After having been kept as a flower 

 garden for eight or nine years, I this spring 

 turned it into a kitchen garden, and for tliat 

 purpose again had it trenched 18 inches 

 deep, and sown with beet- root. About a 

 month ago, when weeding and thinning the 

 beet-root, I observed that a considerable 

 number — perhaps 30 plants — of seedling po- 

 tatoes had sprung up. They were spread 

 irregularly over the whole piece of ground, 

 a few being in the rows with the beet-root, 

 but the greater part in the intervals be- 

 tween the drills. When I last saw them — 

 about three weeks ago — they were looking 

 very healthy, and exhibited considerable va- 

 riety in the shape of the leaves. I have no 

 doubt that they are the produce of seed from 

 the crop of 1832 or 1833, which had been 

 allowed to ripen on the ground, and the 

 seed having been buried 18 inches deep, had 

 remained dormant until brought again to 

 the surface by the trenching this spring. 



Potatoe Disease. — Mr. C. R. Bree said : 

 In September, 1846, I ventured to suggest 

 that we should endeavour to arrive at sound 

 conclusions about the nature and cause of 

 the potatoe disease, by registering and rea- 

 soning upon facts alone. I also stated that 

 for two years I had observed symptoms of 

 the disease for the first time on the 23rd of 

 August. When I observed, therefore, your 

 notice of the 20th ult, that we had nearly 

 escaped the disease, I could not help think- 

 ing that the remark miglit still be prema- 

 ture, and the experience of the last ten 



