Fig. 103. Peronospora of the cabbage. The larger 

 part of the spores have fallen, disclosing the 

 curved terminal branches upon which they 

 were borne. 



This is a fungus disease related to the Potato Murrain, and acting 

 in the same manner. Peronospora 

 parasitica is the parasite, and it is 

 found mostly on young cruciferous 

 plants growing in damp shady 

 places. It is not found on full- 

 grown plants except under unusual 

 circumstances. 



Remedies. 1. Secure good drain- 

 age, especially for seedlings in 

 beds, and look out in general that 

 the place is not too moist and shady. 



2. Destroy at once all affected 

 plants, otherwise the disease is 

 likely to spread from them to other 

 young plants, not only to cabbages, 

 but also to turnips, radishes, and 

 other crucifers. 



3. I know of no experiments with fungicides made upon this parti- 

 cular fungus, but the use of Bordeaux mixture is effective with the 

 potato blight or murrain, and some others of a similar character. I 

 therefore have no doubt that the Bordeaux mixture could be applied 

 with good effect. Cabbages will stand the application of the mixture. 

 It should not be applied in the middle of warm sunny days, but in the 

 morning or evening, or on cloudy days. One or 



two applications, I think, would be sufficient. 

 The first two measures should suffice unless con- 

 siderable money is at stake. 



If a bed has to be destroyed on account of the 

 disease it would be best to disinfect it with boil- 

 ing hot water or by sprinkling thoroughly with 

 concentrated solution of sulphate of iron. Facts 

 that should be remembered are that the disease 

 is very likely to spread down hill, and in the 

 direction of the prevailing wind. 



Fig. 104. Final ramifications 

 of the mycilium of Cab- 



bage Peronospora as grown 

 in water culture ; showing 

 the peculiar dichotomous 

 branching mentioned in 

 the text. 



BLACK SPOT OR FUSICLADRJM OF THE LOQUAT. 



[See Coloured Plate, Frontispiece.] 



THERE is a disease of the Loquat very common some seasons, much 

 less so others that deserves mention, though it is among the pests of 

 minor importance, unless indeed the disease proves to be dangerous 

 to other vegetation. I refer to the " Black Spot" of the fruit of this 

 tree. Though most apparent on the fruit, it occurs also on the foliage, 

 in this respect resembling the Fusicladium fungus of the black spot of 

 the apple and pear, to which it is very closely related, to say the least. 

 The specific differences among these various fungi seem to me to be 

 open to question, but I am not yet prepared to publish evidence such 

 as that given on previous pages in connection with the ripe rot fungi. 

 The chief object of this note is to call attention to the precise 

 appearance of the disease, and to the fact that it may be combated in 



