143 ox THE CHEMISTRY AND TOXICOLOGY OF FUNGI. 



upon attention ; for persons new to the subject appear to find a 

 difficulty in receiving the idea of discrimination. Thej are domi- 

 nated by the erroneous notion that species of Fungi differ Httle 

 from one another, and that a few broad generalized distinctions 

 are enough to know. But though all Fungi have much in common, 

 there are not onlj- external features but also elements of their 

 composition Avhich divide the mo^st closely allied species from one 

 another, and which give to each a distinctive identity which is 

 fixed and invariable, wherever and whenever that species may 

 grow. 



Various analyses concur in showing that there are certain con- 

 s!:ituents which are held in commoii by all of the larger Fungi yet 

 examined. But there is entii'e difference among the species as to 

 the proportions in which these common constituents are severally 

 blended in them. They are as follows : — 



Water ; sometimes in certain species nine-tenths of the gross 

 "weight. 



Cellulose or Lignose, constituting the fibrous structure of the 

 plant (CioH.gOig). 



Proteids ; namely, a nitrogenized substance insoluble in water ; 

 a second nitrogenized substance soluble in water and coagulable by 

 heat (albumen) ; and a third nitrogenized substance soluble in 

 alcohol (osmazome). 



A fatty matter analogous to wax (adipocere). 



A fatty matter like tallow, resolvable into a fluid (olein), and a 

 body solid and crystallizable at ordinary temperatui^es (stearin). 



Sugar, of the kind called specifically mannite. 



A resinoid matter, which becomes brown on exposure to the air. 



Traces of salts of potash and silica, and of sulphur. 



Over and above the foregoing constituents. Fungi possess others 

 Avhich are not common to all species, but one or other of which 

 may be found in particular species. These peculiar and especial 

 constituents are gelatine, gum, mucilage, bassorine, inuline, dex- 

 trine, glucose, es.sential oils, colouring matter; also citric, malic, 

 oxalic, phosphoric, and fumaric acids; also salts of ])otassium, 

 sodium, and calcium ; and other matters unnamed or not yet 

 isolated, on certain of which may depend the scent and taste of 

 the .species. For the odours and fiavours of Fungi are exceedingly 

 various, and differ very greatly in one species and another, often 

 affording great assistance in the determination of species. Many 

 being peculiar, without common analogues, arc almost impossible 



