HABITATS. 24o 



as well as some species of Stiymatea and DotJiidea. Of the 



genus Sphceria, a considerable number are found on dung, now 



included by some authors under Sordaria and Sporormia, genera 



founded, as we think, on insufficient characters. 



A limited number of species are parasitic on 



lichens, and one species only is known to be 



aquatic. 



We have thus rapidly, briefly, and casually 

 indicated the habitats to which the majority 

 of the larger groups of fungi are attached, 

 regarding them from a systematic point of 

 view. There is, however, another aspect from 

 which we might approach the subject, taking 

 the host or matrix, or in fact the habitat, as 

 the basis, and endeavouring to ascertain what 

 species of fungi are to be found in such posi- 

 tions. This has partly been done by M. West- 



, * , -, , -, Ti , FIG. 109. Torrubia 



endorp;* but every year adds considerably to m mtarit on pupa of a 

 the number of species, and what might have moth ' 

 been moderately accurate twelve years since can scarcely be so 

 now. To carry this out fully a special work would be neces- 

 sary, so that we shall be content to indicate or suggest, by means 

 of a few illustrations, the forms of fungi, often widely distinct 

 in structure and character, to be found in the same locality. 



The stems of herbaceous plants are favourite habitats for 

 minute fungi. The old stems of the common nettle, for ex- 

 ample, perform the office of host to about thirty species.f Of 

 these about nine are Pezizte, and there are as many spha3riaceous 

 fungi, whilst three species of Dendryphium, besides other moulds, 

 select this plant. Some of these have not hitherto been detected 

 growing on any other stems, such as SpTueria urtica and Loplrios- 

 toma sex-nucleatum, to which we might add Peziza fusarioides and 

 Dendryphium griseum. These do not, however, include the whole 

 of the fungi found on the nettle, since others are parasitic upon 



* Westendorp, " Les Cryptogams apres lenrs stations naturelles.'' 

 t Cooke, "On Nettle Stems and their Micro-Fungi," in "Journ. Quekett 

 Micro. Club," iii. p. b'9. 



