120 MICROSCOPIC FUNGI. 



stroll in the grounds^ and when the well-known 

 leaves of the coltsfoot are descried_, the under sur- 

 face of the first leaf will doubtless give proof of the 

 presence of the fungus in question^ by the orange 

 spores amongst its dense woolly hairs. Sometimes 

 the leaf is almost covered beneath with the bright 

 orange-coloured dust. This is the coltsfoot rust 

 {Goleosporiumtussilaginis^ Lev.^ plate VIII. fig.] 80)., 

 which may serve as a type of the rest. It may be 

 observed that a species of cluster-cup^ or JEcidmmy 

 with spores of nearly the same colour^ is also to be 

 found on the leaves of the same plant ; but in this 

 case the upper surface of the leaf has also corre- 

 sponding purplish spots_, and^ what is of still more 

 importance^ the spores are seated in small fringed 

 cups. The rust is common till the wintry frosts have 

 set in^ and is far more conspicuous than the cluster- 

 cups. A kind of di-morphism prevails in all the 

 species of this genus. Some of the pustules resolve 

 themselves into a kind of powder^, whilst others 

 remain entire and solid. Generally there is the 

 largest proportion of globose,, dust-like^ free spores^ 

 produced in the earliest developed fungi^ whilst they 

 become more rare towards the close of the season. 

 The permanent spore-spots consist of obovate 

 cellules placed side by side^ each of which is divided 

 transversely by three or four septa^ and is filled with 

 an orange-red endochrome (plate VIII. fig. 181); 

 the exterior being enveloped in a kind of mucous 

 layer. The arrangement of spores when packed 



