THE HAMILTON ASSOCIATION. 93 



sorbing their fluids. Air spaces are then formed in the centre of the 

 spot, giving rise to the dead white appearance which resuhs. In 

 fig. 19 there is seen the transection of a strawberry leaf, of which the 

 portion on the left is healthy and of the usual thickness, while that 

 at the right shows a margin of the " spot," and this portion of the 

 leaf is shrivelled to one-fifth its usual thickness. At h is seen the 

 reproductive portion of the fungus known as conidia. The conidia- 

 spores are oblong and very minute, and when they fall on the fresh 

 leaf surface, where there is a moisture, soon germinate, bore their 

 way to the epidermis c, and give rise to fresh spots. 



In addition to this mode of propagation by conidia, which are 

 summer spores,_ and short-lived, there are also winter spores grown 

 in sacs called asci. Each ascus, or sac, contains eight ascospores, 

 and these preserve their vitality in the dead leaves through the win- 

 ter, and mature in the early spring. From this explanation it is 

 evident that considerable benefit might be derived by strawberry 

 growers through the plan adopted by some, of burning over the 

 plantation in the early spring, for, in this way the fungus, to a large 

 extent, may be destroyed. 



The fungicide, recommended by Professor Scribner for spray- 

 ing the strawberry bed, is three ounces of carbonate of copper dis- 

 solved in one quart of water, and then diluted with twenty gallons 

 of water. This should be sprayed on the plantation after the crop 

 has been gathered, and repeated once or twice before the first of 

 September. No doubt the Bordeaux mixture would be equally 

 effective. 



Some of the varieties, as the Manchester and the Wilson, are 

 especially liable to this disease, while other varieties, such as the 

 Sharpless, are little troubled with it. 



The Raspberry Anthracnose {Glceosporium venetuni). — 

 This fungus is one which has thus far not prevailed to any great ex- 

 tent in Ontario, But from a late report of the Cornell Experiment 

 Station, we note that it was observed in New York State last 

 season, both on the raspberry and blackberry canes. This may yet 

 become a serious injury to us in Ontario. An instance is given by 

 Prof. Burrill, of a blackberry plantation in Missouri that yielded a 

 profit of $400 one year, which was so reduced by the disease that 

 it scarcely paid expenses the year following. The apparent mjury 



