lO INTRODUCTION. 



almost instantaneous — in one case the Boletus minio-olivaceous, 

 if you barely touch it, it turns to a vivid blue. 



In some cases it assumes different colors. In the case of 

 Lactarius deliciosus the juice is at first, when it exudes, red 

 brick saffron, but soon, when exposed to the oxygen of the air, 

 turns to greenish yellow. The black Russula, when cut or 

 bruised, will soon turn to a brick red, a specific character. 



Some species of Cortinarius turn to an azure blue on being 

 bruised. This change of color to blue is so universally confined 

 to dangerous species, that is given as a caution, that all species 

 which exhibit a blue color, when cut or bruised, should on no 

 account be eaten. 



The chemical analysis of different species of fleshy fungi 

 shows different proportions of the chemical or earthy element. 

 Some also contain a large proportion of water, and very little 

 solid matter. All of the Coprinus group have over 90 per 

 cent, of water. The solid matter consists of phosphoric acid, 

 malic acid, oxalic, magnesia and lime. The organic matter, 

 besides water, are nitrogen in form of protein, starch, and 

 sugar. Nitrogen always predominate, which gives them such 

 nourishing properties, equal to beans or peas. 



There is a peculiar attribute of the mycelium, in some of the 

 fleshy fungi, to produce luminosity or phosphorescens. Many 

 a superstitious way-faring man, being out late at night was 

 frightened out of his wits, by taking this innocent vegetative 

 phosphorescens for a fiery man or Satan himself. There are a 

 number of species, which cause that luminosity : but more 

 especially the mycelium of honey Agaric permeating an old 

 decayed stump. 



Luminosity in fungi has been observed in various parts of 

 the world, and it was nearly always a species of Agaric which 

 has produced the phenomenon. One of the best-known species 

 is the Agaric olearius of the olive tree growing in the south of 

 EuroDe. 



