OF BRITISH FUNGI. 17 



colour of the spores and (if practicable) their form, 

 as shown by the microscope should be determined. 



This catalogue of desiderata will have intimated the 

 points of variation which will be 

 found in different species of Aga- 

 ricus, and which will, some of 

 them, be illustrated by the ex- 

 amples to which we shall here- 

 after more particularly refer. 



The entire mass of Fungi subdivide themselves 

 naturally into two great divisions. In one of these, and 

 by far the largest, the spores, or reproductive bodies, are 

 naked or exposed, generally clus- 

 tered in groups of four, or some 

 multiple of that number. It will 

 be borne in mind that in En- 

 dogenous plants, three is the mys- 

 tical, typical, or representative number, whilst in 

 the alliance of plants now under consideration 

 that typical number is four. The first great division 

 of fungi, in which the spores 

 are naked, is termed SPORI- 

 FERA, or spore-bearing. In 

 the second, or smaller division, 

 the spores are contained in 

 bags, or sacs, called asci, f 



and the division bears the name of SPORIDIIFERA. 



The Sporiferous division of fungi, again, contains four 

 families, which are arranged according to the following 

 distinctive features : In one family, the hymenium, 



c 



