CHAPTER XIII. 



SYSTEMATIC ARRANGEMENT. 



This has already been slightly sketched out^ and the details 

 may be reserved for the characters which follow of the genera 

 of Fungi which occur in Great Britain, and the divisions under 

 Avliich they are arranged. It is impossible here to discuss the 

 various arrangements which have been proposed. The one 

 adopted is that which was given in Dr. Lindley's 'Vegetable 

 Kingdom/ and which, as regards the principal groups, is almost 

 identical with that of Fries. It may be objected that it rests 

 on a single character, but in spite of this objection, I know 

 of no arrangement which gives the true affinities of Fungi 

 better, and if it be recollected that it is impossible to arrange 

 any quantity of natural productions in a straight line so as to 

 exhibit their relations, but that these may be illustrated rather 

 by groups ranged round a common centre, bearing relations 

 to the several groups which surround them, it will be seen, I 

 think, that the arrangement does place together those species 

 which are closely allied, though connected also with others in 

 a contiguous group. Thus the Uredines pass through Podisoma 

 into the Tremellinm, and Botrytis, or Sporotrichwn, through 

 Isaria to Clavati. When the sporidia in an ascus are reduced 

 to one, and the sac fits closely to the sporidium, the body so 



