28 



CULTURAL STUDIES OF SPECIES OF PENICILLIUM. 



continuing for some weeks to produce great numbers of conidia which come to form 

 masses perhaps 1 mm. in thickness. Conidiiferous cells 8-10 by 2-3/f. Conidia 

 elliptical to globose 2 by 3.3/t or 3-3.4/c, green, homogeneous, persisting in chains 

 when mounted. Colonies begin to liquefy gelatin slowly after about 10 days and 

 continue until it is completely liquefied. Grows readily and rapidly upon all com- 

 mon media. 



Occurs characteristically upon decaying apples-and other pomaceous fruits, where 

 old colonies often produce coremia 1 cm. or more in length and very large. 



Collected at Ithaca and Geneva (Eustace), N. Y., at Middletown and Storrs, Conn., 

 upon apples; upon pears and Mespilus at Hanover, Germany. Often appears as a 

 contamination in fungous cultures. 



Fig. l.—Penicillium expansum Link: a, b,f, branching and arrangement of branches of conidial fructifi- 

 cation (X 900); c, d, e, conidiiferous cells and conidial chains (X 900); g, ft, j, k, I, sketches of fructifica- 

 tion (X 140); m, n, o, germination of conidia (x 900); r, s, sketches from photomicrographs, showing 

 in s loose aggregations of conidiophores beginning to develop in zones which become coremia like r 

 (coremium r was 1 mm. in height; X 35). 



Many references in the literature to P. glaucum Link and P. crusta- 

 ceum (L.) Fries refer to this species. Unless, however, such citations 

 directly refer to the presence of coremia, or to the association of the 

 organism with the decay of pomaceous fruits, or both, there is no 

 means of fixing the application of such names to this species. Since 

 Link 11 in 1824 lumped into his specie's P. glaucum every kind of green 



