SCIENTIFIC COMMITTEE, AUGUST 20. 



clxiii 



Scientific Committee, August 20, 1907. 



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



present. 



Tomato Disease caused by Septoria Lycopersici. — Mr. Giissow 

 showed specimens of Tomato leaves from Gloucestershire having brown 

 spots. These quickly cover the whole leaf, which dies in the course of a 

 very few days after the infection commences. The disease does not seem 

 to have been recorded in this country hitherto, although it was found in 

 Argentina as long ago as 1881. There seems to be no remedy after the 

 plants are once attacked, since the progress of the trouble is so rapid, 

 but plants attacked should be burned immediately. 



Neobenthamia gracilis, Eolfe. — A spike of this very pretty Orchid from 

 Zanzibar was shown by Mr. Bennett-Poe, V.M.H. It was awarded a 

 Botanical Certificate in 1900, and is described by Mr. Rolfe in the 

 Gardeners' Chronicle, 1891, ii. p. 272, and figured in Bot. Mag. 1900, 

 tab. 7221. 



Aphides on Palm Boots. — Mr. Gordon, V.M.H., showed portions of 

 the root of Kentia Forsteriana upon which were large numbers of a 

 species of woolly aphis. The plant from which the specimen had been 

 taken did not appear to have suffered to any extent from the attacks 

 of the insects. They were referred to Mr. Saunders for further 

 examination. 



Beappearance of a Peach Pest. — Dr. M. C. Cooke, V.M.H., showed 

 figures of a pest of Peaches which " the late Rev. M. J. Berkeley recorded 

 and figured in the Gardeners' Chronicle for 1864, p. 938. This mould 

 Berkeley discovered on ripe Peaches in Wales, where he found it to be a 

 pest producing a great profusion of large spores. He named the fungus 

 Macrosporium rhabdiferum ; but as the spores were not muriform 

 it could not be Macrosporium. In/ the ' Handbook ' I called it 

 Hclminthosporium rhabdiferum, but now that I have seen it I find it 

 is not Helminthospormm. In the interim it appears not to have been 

 met with anywhere, until last week it turned up on Peaches again — after 

 everyone had given it up as a mystery, and it was excluded from all 

 consideration as a pest. There can be no doubt of its being Berkeley's 

 species ; it agrees so well with the description and the figure. The 

 spores are so profuse that it would be dangerous as a pest were it to 

 obtain a foothold." (See p. 527.) 



Plum Anthracnose. — Dr. Cooke also said : " Some Plums have 

 recently been submitted to me which were evidently suffering from the 

 attacks of a new pest. The surface of the nearly ripe fruit exhibited 

 one or two concave depressions, about a quarter of an inch in diameter, 

 and of a pale tan colour, contrasting strongly with the deep purple of 

 the fruit. These depressions were lined with the minute receptacles of 

 species of Anthracnose, as the Americans term this form of disease, 

 produced by species of the genus Gloeosporium. In this instance the 

 spores were abundant in the depressions, hyaline, but comparatively very 

 small for the genus, not more than 10 to 12 mm. long, and about 

 one-fourth as broad. Hitherto I have found no described species to 



d v 2 



