Some Concepts in Mycology. William B. Brierley. 217 



"species" here are merely "ecads," and in no wise comparable 

 with species of Penicilha as described by Thorn (15) or species 

 of Fusaria as diagnosed by Appcl and Wollenweber(i) or more 

 recently by Sherbakoff(39). The "species" of Agaricus like 

 the "species" of most other genera of fungi correspond to the 

 morphological variants or "ecads" obtained by the expcrimen- 

 taHst when a particular pure line organism is cultivated under 

 different environmental conditions. 



It would be advantageous if there could be introduced into 

 systematic mycology some such terminology as that proposed 

 by Lotsy(^3) for the phanerogams. Perhaps the main features 

 of this as they apply to fungi may briefly be noted here. 



The term Linneon is suggested to replace the term species 

 in the Linnean sense, and to designate a group of individuals 

 which resemble one another morphologically more than they 

 do any other individuals. To establish a Linneon conse- 

 quently requires careful morphological comparison only. 



The name Joydnnon to replace the term species in the Jor- 

 danian sense, viz., microspecies, elementary species, subspecies, 

 etc., and to designate a group of individuals externally alike 

 which all propagate their kind faithfully as far as these external 

 characters are concerned, with the only exception of non- 

 inheritable modifications of these characters, caused by the 

 influence of the surroundings in the widest sense, to which these 

 individuals or those composing the progeny may be exjwsed. 

 To establish a Jordanon, morphological comparison alone does 

 not suffice; the transmittability of the characters by which 

 the form was distinguished must be proved by experimental 

 breeding. 



The name Species to designate a group of individuals of 

 identical constitution. To establish a species neither morpho- 

 logical comparison alone, nor comj^arison of the morpho- 

 logical facies of the organisms on standardised series of culture 

 media is sufficient. Analysis of physiological reaction to 

 standardised conditions is required in addition. 



The term Modification to designate the non-transmittable 

 effect of external circumstances. 



The continuance of the present system, or lack of system, 

 in mycological terminology can only add to the existing con- 

 fusion, and make still deeper and more unbridgeable that ever- 

 widening gulf between the work of the systematist and that of 

 the laboratory and field experimentalist. The adoption of the 

 terminology suggested by Lotsy, which involves the acceptance 

 of the physiological species concept, would not only co-ordinate 

 the systematic treatment of fungi with that of the other great 

 groups in the vegetable kingdom — and surely there is not a 



