26 CULTURAL STUDIES OF SPECIES OF PEXICILLTUM. 



On page J!) <>f his " Observationes " Link describes the genus 

 Coremium with a single species, C glaucum, which he specifies as found 



upon decaying fruits. This fungus can be traced through a con- 

 nected series of publications giving descriptions and figures which 

 show the original conception to include (if not entirely to be drawn 

 from) the large green coremia which develop upon apples and related 

 fruits decaying in storage. 



This organism is figured by Greville 8 as Floccaria glauca; it is cited 

 cited by Fries 7 as a variety of Penicillium crustaceum, from which he 

 has "seen it originate upon apples in the autumn." It is twice 

 referred to by Corda in Icones Fungorum (Vol. II, p. 17); he cites 

 Coremium glaucum, C. cUrimum, and 0. candidum as synonyms; 

 again in Prachtflora (p. 54, taf. XXV, figs. 3, 4, 17, 18, 19, 20, and 21) 

 under the name of Coremium vulgare he manifestly had this same spe- 

 cies, although he groups it with figures which appear to be different 

 organisms. 



These figures and descriptions cited are definite enough to show 

 that workers contemporary with Link applied the name Coremium, 

 glaucum Link to the coremiform rot of the apple. As a result of 

 observations of living material Fries considered this only a form 

 of Penicillium crustaceum, which he made to include P. glaucum and 

 P. expansum Link. 



The present writer has collected this fungus upon decaying apples 

 and related fruits repeatedly in America; also upon pears and 

 mespilus in Hanover / Germany. 



Repeated cultures have shown that the ability to produce coremia 

 is a definite character of this species, recognizable under many con- 

 ditions of culture, but not shown under other conditions. The same 

 culture will commonly show both simple penicillate fructifications 

 and coremium production. The species must therefore be regarded 

 as one of the several species of Penicillium which always produce 

 coremia under proper cultural conditions. 



Examining Link's species of Penicillium , we find that he specifies 

 P. expansum as primarily found upon rotten fruit. P. expansum 

 Link clearly included Coremium glaucum Link, therefore, probably 

 with others; but from its known abundance in Germany there can 

 be little question as to this organism forming in part, at least, Link's 

 original conception of this species. Later (1824) in Species Plan- 

 tarum, Tomus VI, page 70, Link 11 redescribes P. glaucum and includes 

 in it the P. expansum of his Observationes. In this discussion Link 

 broadens his description of P. glaucum to include all green forms 

 found in decaying substances, upon the assumption that all such 

 forms are but a single species. It is evident that the earlier descrip- 

 tion P. expansum Link included this species with sufficient restriction 



