FUNGOID PESTS OF CULTIVATED PLANTS. 73 



may not hesitate to attack living plants in the same way as the Snowdrop 

 species. 



It forms dark smoky tufts, which sometimes unite in a larger effused 

 mass. The threads are comparatively thick and rather closely jointed, 

 attenuated upwards towards the apex, where they are slightly and sparingly 

 branched, downwards of a pale olive colour, but uncoloured in the upper 

 portion. Conidia elliptical, hyaline (15-18 x 8-10 //), collected together 

 at the tips of the threads, or of the branches, in small glomerules or clusters 

 of from three or four to seven or eight conidia. In this respect the present 

 species appears to be rather peculiar, since the head or glomerule of conidia 

 in most cases contains a large number of individuals. 



It has to be discovered whether this species is capable of providing 

 itself with sclerotia and of developing therefrom the customary Sclerotinia. 



Grevillea, xvi. 10 ; Sacc. Syll. x. 7165. 



COPPER WEB. 

 Rhizoctonia Crocorum (DC.). 



Amongst the diseases to which the Crocus, especially the Saffron 

 Crocus, is subject is one which has long been known under the name of 

 " copper web." This is due to the presence of a parasitic fungus which lives 

 and thrives at the expense of the Crocus corm. The fungus was classed 

 amongst the Truffles by Duhamel in 1728 and afterwards figured by 

 Bulliard under the name of Tuber parasiticum, which was afterwards 

 changed by Persoon into Sclerotium croceum ; but it was De Candolle who 

 finally raised it to the dignity of a genus and called it Rhizoctonia. 



This singular parasite consists of Sclerotia -like tubercles united by 

 byssoid filaments going from one to the other and forming a sort of sub- 

 terranean web or net. It is by means of these filaments, which are 

 attached to the rootlets of the plant or which creep over the surface of the 

 bulbs after having pierced their integuments, that the parasite appropriates 

 their nutritive juices after the manner of the "Dodder," and induces, if 

 not direct death, at least a weakly development. 



It was doubtful for a long time whether any real fructification was 

 produced ; and even now it is uncertain, although Broome found, on what 

 he considered the same web on Mint, not only the hard warts, but little 

 tawny tufts of a looser texture covered with globose or ovate spores. It 

 seemed evident that the tufts and warts were forms of each other, but 

 whether the spores were the true fruit, or only a secondary form of fruit, 

 has not been determined. 



Journ. B.H.S. vol. v. 1850, p. 23. 



NARCISSUS BRAND. 

 Puccinia Schroeteri (Pass.), PI. V. fig. 89. 



The leaves of Narcissus have recently been found in this country to 

 be affected with a disease which apparently originated in Italy and after- 

 wards extended into Germany. 



The spots are large and oblong, with a tawny- violet border ; the pustules 

 are produced on these spots, and either solitary or a few together, either 

 covered with, or girt by, the remains of the ruptured epidermis. 



