Report on Botany. 



37 



A Hand-book of British Fungi is in course of preparation, 

 the first part of which is now ready for distribution to sub- 

 scribers. The author is M. C. Cooke, who is already 

 favorably known to the public through his popular works 

 on Microscopic Fungi, British Fungi, etc. It is his purpose 

 in the present work to give descriptions of all known 

 species of British fungi, and to illustrate all the principal 

 genera. The appearance of the second part of the work 

 will be anxiously awaited by mycologists. But we take 

 special pleasure in calling attention to an article recently 

 published in the Journal of Botany, under the title of Clavis 

 Agaricinorum. The author is W. G. Smith, a gentleman 

 who has given much attention to the study of agarics. 

 In this article, while following pretty nearly the system- 

 atic arrangement of the genus Agaricus as laid down by 

 Fries and Berkeley, he thinks their passage from the sec- 

 tions depending on the color of the spores, to subgenera, 

 is too abrupt. He therefore makes another division inter- 

 mediate between these and depending on the character of 

 the pileus and the stem. In each of the five primary sec- 

 tions, which depend on the color of the spores, he makes 

 three secondary divisions or subsections characterized as 

 follows : 1st. Hymenophorum distinct from the fleshy 

 stem; 2d. Hymenophorum confluent and homogeneous with 

 the fleshy stem ; 3d. Hymenophorum confluent with, but 

 heterogeneous from the cartilaginous stem. The first sub- 

 section contains theoretically three subgenera ; the second, 

 four ; and the third, three. But in no section are all the 

 subgenera here indicated actually known to exist. And 

 just here is the remarkable feature of Mr. Smith's article. 

 It really indicates the characters of subgenera of which no 

 members have yet been found. In the section of white- 

 spored agarics, the third subgenus is vacant, no white- 

 spored species being at present known that does not find 

 a place in some one of the other subgenera of this section. 



