328 



Notes on Mildew, from 



or smut, which is destructive not only of barley, but also of 

 wheat and oats. The [/redo ASegetum, or smut, has been the 

 subject of many interesting experiments by Mr. Bauer of Kew, 

 whose discoveries will no doubt throw very considerable light 

 upon the subject. It not only destroys the grain, which it 

 converts into a kind of jelly, but it attacks the leaves and 

 stems, always forming in the interior of the plant, and burst- 

 ing forth when ripe. Corn is also at- 

 tacked by a species of Puccini^, a very 

 fatal kind of fungus, which always ap- 

 pears divided into cells. Puccinia Gra- 

 minis f^^-. 95.), which attacks corn, 

 forms in the interior of the stalk, and, 

 when ripe, bursts forth in clusters, like 

 bunches of grapes, of a dark brown 

 colour. Puccinia Rbsse Grev. {Jig- 96.) 

 appears on the leaves of rose trees, in 

 little brown tufts, which, when opened 

 and magnified, are found divided into 

 extremely minute cells. A correspond- 

 ent of this Magazine (Vol. IV. p. S20.) 

 mentions that his celery was infected 

 with ferruginous spots, occasioned, no 

 doubt, by the Puccinia i:?eracle? Grev. ; and another cor- 

 respondent, Mr. Robert 

 Errington (Vol.V. p. 107.), 

 gives a detailed account of 

 the manner in which his 

 celery was attacked by the 

 same disease, and of the 

 means which he adopted 

 for its cure. He describes 

 his celery as having the appearance of having been scorched 

 by fire. He says he dug up the infected plants, and buried 

 them, but this only seemed to increase the evil ; and he tried 

 several other remedies, but without any permanent success. 



It is a vulgar error to suppose that a berberry tree {Ber- 

 heris vulgaris L.), if planted in a corn field, will, if infected 

 with mildew, communicate the disease to the corn. This 

 cannot be the case, as the mildew which attacks the ber- 

 berry (^cidium Berberidis Pers.,7%. 92.) is quite different 

 from any of the fungi which are found on corn. The ber- 

 berry mildew, when magnified, is found to consist of a number 

 of small orange cups with white films over each. When ripe, 

 these lids burst, and the top of the cup assumes a ragged 

 uneven appearance, like white fungi. Each cup has within 

 it a number of little boxes containing seeds. The mildew 

 on the pear tree is called ^cidiuni cancellatum {Jig. 97.) [See 



