AGAKICINEAE. 299 



condition is when the gills are rounded off behind ( = nearest 

 to the stem), and do not touch the stem, when they are said 

 to be free. Between the two extreme modes of attachment 

 already described, transitional stages exist; when the gills 

 reach the stem and grow to it without being either decurrent 

 or narrowed at the point of attachment, they are said to be 

 adnate. When the gills are attached to the stem, but not by 

 their whole width, in other words when the gill is more or 

 less narrowed at the point of contact with the stem, the term 

 adnexed is used ; finally, when the adnexed type of attach- 

 ment has the narrowed part of the gill close to the stem cut 

 away in a curved manner so as to leave an evident channel 

 between the gills and the stem, the term sinuate is used. 



The primary divisions "of the Agaricineae are founded on 

 the colour of the spores, and while admitting that this is a 

 purely artificial arrangement, it is certainly a very con- 

 venient and practical one, and in a purely systematic work, 

 where the primary object is to enable the student to deter- 

 mine the name of a given species a necessary preliminary 

 to morphological or physiological work is admissible. 



The large genus Agaricus, as understood by Fries, is 

 broken up by that author into several subgenera ; in the 

 present work all the Friesian subgenera of Agaricus are 

 elevated to generic rank, for the two following reasons : 

 (1) Many genera included in the Agaricineae by Fries, as 

 Corlinarius, Paxillus, &c., are quite as closely allied, or even 

 more so, than the Friesian subgenera of Agaricus are to each 

 other. (2) In describing a species of Agaricus from the 

 Friesian standpoint it is necessary to include the subgeneric 

 name in brackets thus : Agaricus (Pmlliota) campestris ; this 

 unnecessarily long name is reduced by raising the sub- 

 genera of Fries to generic rank, and as a genus is not 

 stereotyped in nature as such, more good than harm is 

 effected by the change, except to those minds who consider 

 every departure from accepted custom as retrograde. 



AGAKICINEAE. 



Hymenium borne on lamellae, situated on the under 

 surface of the sporophore, rarely in the simpler types on 

 the upper surface, and consequently turned to the light. 



