FUNGI. 151 



sexual or asexual condition can under certain conditions 

 repeat itself for an indefinite period. 



Until recently every detached fungoid development, 

 provided with any kind of spore-formation, was considered 

 as_ a distinct species, consequently the asexual forms of 

 numerous species were considered not only as distinct 

 species, but distinct genera, that were usually located in 

 a different order to the one in which the second stage of 

 the same individual was placed. As an illustration of the 

 above, numerous forms of minute fungi, producing naked 

 spores at the tips of erect branches, and closely agreeing 

 in structure, constituted a genus called Botrytis. This genus 

 was considered autonomous until it was clearly demonstrated 

 that one of the species, Botrytis cinerea, produced a sclero- 

 tium which, after a period of rest, gave origin to one or 

 more complex sporophores of a higher development than 

 the Botrytis form, and agreeing in every point with the 

 genus Peziza, where the spores are produced in asci — asco- 

 spores — and consequently belonging to the Ascomycetes. 

 Such genera as Botrytis, that include forms now known to 

 be conditions of other species, are called forni-genera, and 

 the components are termtA for ni-species. 



Various schemes of classification of the fungi have been 

 propounded from time to time; the one adopted in the 

 present work is by Brefeld, which is based as far as possible 

 on a knowledge of the life-history of typical forms, and in 

 this respect differs from earlier ones, which in most instances 

 depend on morphological points of agreement presented 

 by mature forms. 



According to this author, fungi are divided into two 

 primary groups, the Phycomycetes, or algal-like fungi, charac- 

 terized by sexual as well as asexual modes of reproduction, 



