80 FUNGOID PESTS OF CULTIVATED PLANTS. 



Seldom of sufficient importance to demand a remedy, but in such 

 case spraying of young plants might be beneficial. 

 Sacc. Syll iii. 207. 



Another species (Phyllosticta Napi) is known in France, but is very 

 little different in appearance, and a slight difference in the form of the 

 sporules. 



A leaf-spot with two-celled sporules (Ascochyta Brassicce) is known 

 on the Continent, forming large irregular bleached spots, on which the 

 receptacles are densely crowded. The sporules are fusiform, septate and 

 nucleate (15-16 x 3-4 /*). 



CABBAGE ANTHRACNOSE. 

 Glwosporium concentricum (Grev.), PL VII. fig. 96, sporules. 



In 1851 attention was called to this parasite by a memoir in JOURNAL 

 R.H.S., in which it was stated that the fungus was discovered by 

 Dr. Greville thirty years previously; but never constituted itself a pest 

 until the former year. 



It forms on both surfaces of the leaves of Cabbage and Cauliflowers, 

 roundish, often confluent, patches, consisting of little white specks 

 disposed more or less concentrically, those of the centre frequently 

 becoming yellow, and at length fading away. 



The sporules are developed beneath the cuticle, and are oblong and 

 cylindrical, often curved, containing two or three nuclei (about 20 x 7 fj) 

 borne upon short delicate spore -bearers. These sporules are mixed with 

 a viscid fluid, and in dry weather ooze out through the fissures in the 

 cuticle as rude irregular tendrils. There is no trace of a perithecium, 

 only a subcuticular cell, in which the sporules are developed. The 

 tendrils are dissolved with moisture, and the sporules are disseminated 

 over the leaves. 



This fungus has also been found in Germany, but nowhere has it 

 become a troublesome pest, and, as far as we can learn, is only an 

 occasional visitor. 



Sacc. Syll. iii. 3665 ; Journ. E.H.S. vol. vi. 1851, p. 117, with fig. ; 

 Cooke, Hdbk. 1408. 



There appears to be no chance of discovering what Cercospora 

 Bloxami B. and Br. can be. It was imperfectly described, and the 

 supposed original specimens have no fruit (PL VII. fig. 97). 



CABBAGE WHITE BUST. 

 Cystopus candidus (Pers.), PL VII. fig. 98 a, b. 



This is a very old and very common offender, and is not confined to 

 Cabbages, but extends its ravages to almost any Cruciferous plant. It 

 was described by Berkeley in 1848 as White Bust, and was then believed, 

 and long afterwards, to be related to the ordinary rusts, but recently, 

 when better known, it has found a place near the Rot Moulds. 



The external appearance consists of swollen, convex, white pustules, 



