CRYPTOGAMIA FUNGI. 131 



decayed leaf, and confined to the under surface. On beech 

 leaves I find a variety not visible without a magnifier, and 

 apparently confined to the upper side of the leaf. 



57. S. lichenoideS) capsules very minute, black, immersed, pro- 

 minent, clustered on dead spots of living leaves. DECAND. Fl. 

 Franc, ii. 299. and vi. 147- Xyloma lichenoides, Ibid. ii. 304. 



Hob. On leaves of trees and herbaceous plants in summer. 



The leaves of some trees and herbs, even when in. full vigour, 

 may be observed to be marked occasionally with dead spots 

 produced by an absorption of their parenchyma and colour- 

 ing matter. On these spots we can often detect black dot- 

 like Sphaeriae scattered in profusion, and to all such, I 

 would, in this work, extend the name of licTienoides. Whe- 

 ther the parasite is the cause of the death of the part, as 

 DECANDOLLE thinks, or whether the part, by its decay, has 

 merely been brought into a state favourable for its deve- 

 lopment, is doubtful ; but on the same tree I have found 

 spotted leaves, some with and some without Sphaeriae, a 

 fact which tends to support the latter opinion. The fol- 

 lowing varieties have been observed in this neighbourhood : 



a. Spots subcircular, brownish, bounded by a darker line ; sphae- 

 riae on the upper side. Leaves of the ash and ivy. 



b. Spots subcircular or irregular, eaten, netted by the reticula- 

 tion of the leaf; sphgeriae on the under side. Leaves of the 

 mapple. 



c. Spots subcircular, brown, bounded by a slight thread-like 

 line ; sphaeriae on the upper side. Leaves of the common avens. 



d. Spots circular, pale, surrounded by a purple halo ; sphaeriae 

 immersed, on the upper side. On the leaves of the common docks. 

 (Probably a distinct species.) 



e. Spots irregular, brown, limited by the reticulations of the 

 leaf; sphaeriae very minute, on the under side. Leaves of the 

 French willow. 



SPRENGEL, in his Systema Vegetabilium, has described 360 

 species of this genus, and FRIES, a later author, is said to 

 have made them upwards of 500. The fact affords a very 

 striking illustration of that variety in his works which the 



