34 British Fungi, 



tliat no atfcempfc has been made in tliis direction, and 

 it is probable that in many cases the higher form of a 

 species has been completely arrested, the gonidial 

 phase alone remaining. And again, in many instances 

 where two forms of reproduction have been clearly 

 proved to exist, it has been shown that the two forms 

 need not necessarily alternate, but that either form, 

 more especially the gonidial phase, can reproduce itself 

 for an indefinite period, the sexual or higher form 

 being rarely developed. 



Tulasne was the first to indicate clearly the fact 

 that numerous forms hitherto accepted as species were 

 but phases in the development of other fungi, and 

 this condition of things he called fleomoriphism^ which 

 is the term at present used to express the occurrence 

 of more than one independent form in the life cycle 

 of a species, and as already stated, pleomorphic fungi 

 are the rule rather than the exception. Tulasne's 

 discovery has been developed and rendered practicable 

 by the exact method of conducting artificial cultiva- 

 tions introduced by De Bary, to whom more than to 

 any other individual we are indebted for the know- 

 ledge we possess relating to the morphology and 

 pleomorphism of the fungi. The fact of two or more 

 forms growing in close proximity or even apparently 

 from each other, or follo^ving each other always in 

 the same order of time, does not prove that such 

 forms are stages m the development of one individual; 

 such occurrences may be accepted as suggestive, but 

 it must ever be remembered that the only proof of 

 two or more forms being stages in the life cycle of 

 one species depends on being able to produce the one 



