498 Retrospective Criticism. 



in vindication of our method of training the peach and nectarine trees j 

 but the manner in which Mr. Hayward has treated it calls for a reply, 

 which I shall endeavour to give as concisely as possible. In Vol. VIII. 

 p. 654. fig. 124., Mr. Hayward has given a drawing, considerably more like 

 F. N. B.'s pear trees (Vol. II. p. 262.) than my father's peach trees 

 in the same volume (p. 296.). Mr. Hayward charges us with losing an 

 angle of 45° at the bottom of the wall ; but I am at a loss to know where 

 he finds his grounds for such observations, for our tree has its lower 

 branches nearly horizontal. We certainly, while a tree is young, give it a 

 considerable elevation, to promote an equal distribution of sap ; but, as 

 soon as we find the tree sufficiently strong in its lower branches, these are 

 thrown down to a line horizontal with the base. Mr. Hayward has endea- 

 voured to make our method conformable to his 7th rule, by placing the 

 leading branches at an angle of 45°; to which rule we have no pretensions, 

 for our leading branches pass through all the degrees of the quadrant, from 

 the horizontal to the perpendicular. But I beg to inform Mr. Hayward, 

 that the plan which we adopt to produce an equal distribution of sap is, to 

 to increase the number of our secondary leaders as the main leaders 

 advance in elevation and increase in strength. By these means, we con- 

 siderably shorten the stem of our trees, and keep that command over 

 them which enables us to reform them should we lose a branch by any 

 accident; for, in that case, we have only to loosen the tree, above the 

 failure, and bring the branches down. There is generally sufficient wood 

 in the centre to supply the deficiency; but, if not, we have only to lay the 

 leading branches a little more distant from each other. Mr. Hayward 

 supposes that we may have gained some information from his works on 

 horticulture; but I can assure him, that neither my father nor I have ever 

 seen any of his writings but what have appeared in the EncyclopcEclia of 

 Gardening and in this Magazine. I am. Sir, yours, &c. — William Sei/mour. 

 Palace Gardens, BishopthorjJCy July ^. 1833. 



Facts on the JEcidiiim cancelldtum Sowerby ; its Germination sitppiosed to 

 occur on Leaves while these are enfolded in the Buds of Trees ; and a Sugges- 

 tion for extirpating the JEcidium. — Sir, Much has been written in your 

 Magazine respecting mildew and blight ; and in Vol. VIII. p. 738, 739., are 

 queries on that destructive parasitic fungus jEcidium cancellatum. I think 

 any one that is in possession of any facts relative to it, be they ever so few, 

 cannot bejustified in withholding them from his fellow-men. Impressed with 

 this feeling, I send you a few observations which I have made on it. The 

 ^cidium cancellatum first makes iis appearance, discernibly to the naked 

 eye, as soon as the leaves have expanded themselves, in the form of little 

 red spots on the upper surface of the leaf, as Mr. Merrick has described in 

 Vol. IX. p. 333. Question, Has not the fungus been growing ever since the 

 leaves began to protrude from the scales that enclose them in the unex- 

 panded state ? or how could the fungus attain the size to be visible at a 

 distance from the trees on which it is growing, by the time the leaves have 

 become expanded ? This appears to me very likely to be the case, as the 

 fungus is nearly three months from this time before it arrives at maturity ; 

 consequently, it is not one of those species of fungus which require only 

 twenty-four hours from the first springing of the plant to the ripening of 

 its seed. From red it changes to a bright orange ; and, when examined 

 with a microscope, is found to contain a number of dark spots, rising a 

 little from the surface of the leaf, and covered with a honey-like sub- 

 stance. I have also observed drops on the leaves, that seemed to proceed 

 from the orangy blotches; and these, when the tongue is applied to them, 

 have a sweet flavour. This I have observed to take place on the upper 

 surface of the leaf, before the pale brown, teat-like, miniature bags (peri- 

 dia) are projected from the woody excrescences on the under side. 



With respect to the question by J. D. (Vol. IX. p. 332.), by virtue of 



