The SpBATiNa of Orchaeds. 295 



the powder the young rose leaves were attacked to such ar extent that 

 it was doubtful if any beneficial results followed the applications. It 

 was Mr. Boole's opinion, after using fostite during the period men- 

 tioned, that the benefits derived did not pay for the material and the 

 labor of applying, for the young leaves showed spots of mildew almost 

 as soon as they unfolded. This result may be partially explained by 

 the fact that young rose leaves do not as a rule assume such a horizon- 

 tal position as do the old ones; they have a wilted appearance. Their 

 surfaces also seem to be more smooth and glossy. It is very probable 

 that the powder failed to adhere to the young leaves, and these were 

 then open to the attacks of the mildew. In this trial the time was 

 short but the roses were growing so rapidly that the fungicide had a 

 fair chance to protect the young foliage. 



Another experiment upon roses was carried on in the rose-house of 

 this station. About twenty-five of the leading market varieties of tea 

 roses were under treatment. When the plants were set in the house 

 some of them showed considerable amounts of mildew, but most of the 

 varieties were free from the disease. Fostite was immediately applied 

 and the foliage was treated every other day. The powder could be 

 seen very plainly upon the older leaves. When the plants started into 

 growth the condition of the new foliage was watched ' with interest. 

 Mildew appeared upon the young growth to a considerable extent; and 

 although applications were continued for about four weeks no decrease 

 in the amount of mildew could be observed. In neither of these experi- 

 ments was any distinct injury from the use of fostite noticed. 



During the past summer a crop of cucumbers was grown under glass. 

 The varieties grown were Telegraph, SioQ House, Duke of Edinburgh, 

 Blanc Hatif, and White Spine. In July, mildew ( Oidium erysiphoides 

 var. Gucurbitarum ) was observed upon some of the ' foliage, but 

 especially upon Blanc Hatif and Telegraph leaves. The house was 

 shut up, the plants syringed, and fostite applied by means of a bellows. 

 The amount applied was supposed to be ample but not excessive. No 

 apparent injury following this treatment, it was repeated in a few days. 

 Three days later some of the leaves showed signs of injury and soon all 

 the foliage showed a greater or less amount of scorching. No further 

 applications were made. 



In order to test more carefully the exact amount of injury done to 



the foliage of cucurbitaceous plants Individual plants of forcing 



musk-melons were dusted by means of a can having a perforated cover. 



The varieties treated were particularly adapted to forcing and were as 



follows: Melon de Malte, Erode de Malte, Erode d' Antibes blanc 



Erode olive, Erode vert. The apj]i(ali(rs wue nade abcut Octcltr 



