FUNGI 79 



most varied types of fungi, Phycomycetes, Prenomycetes, and 

 Basidiomycetes. 



Endotropic mycorhiza are not developed externally on the 

 rootlets, neither in the epidermal cells, but the mycelium 

 penetrates into the cortical cells of the root, where it forms 

 coils, which often completely envelope the nucleus. Even- 

 tually the coils of hyphae become emptied of their contents, 

 and it is assumed that in the first instance the fungus derives 

 nourishment from its host, which is afterwards reabsorbed 

 by the host. Endotropic mycorhiza are abundantly de- 

 veloped in the roots of orchids and many other monocoty- 

 ledons, also according to Frank, in members of the Ericaceae, 

 Epacridaceae, Empetraceae, and other plants living in 

 humus in moors, heaths, woods, etc. 



Root-hairs are not suppressed by the presence of endo- 

 tropic mycorhiza. 



There is considerable diversity of opinion, even amongst 

 those who have paid most attention to the subject of myco- 

 rhiza, as to whether plants do in reality benefit by their 

 presence. 



Frank, Ber. d. deutsch. Bot. Ges. (1885). 



MacDougal, Ann. Bot., 13, p. 3 (1889). 



Massee, A Text-book of Fungi, p. 142 (1906). 



Stahl, Pringsh. Jahrb., 34, p. 539 (1900). 



Ward, Ann. Bot., 13, p. 549 (1889). 



Woronin, Ber. d. deutsch. Bot. Ges., 3, p. 205 (1S55). 



FUNGI 



It is not possible in this place to give a detailed account 

 of the peculiarities and mode of life of the fungi ; for such 

 information, books devoted to the subject must be consulted. 

 The horticulturist as a rule equally condemns all fungi, and 

 considers that only injury can result from their presence. 

 This however is not so ; myriads of noxious insects are 

 destroyed by fungi, the most familiar example perhaps to the 

 ordinary non-observer being the common house-fly, fixed to 

 a window-pane, and surrounded by a halo of fungus mycelium. 

 Caterpillars, many of large size, are preyed upon and eventu- 

 ally killed by fungi in every part of the world. The cater- 

 pillar is infected with fungus spores while still alive, but is 



