616 A MANUAL OF THE PENICILLIA 



hyphae bearing very short conidiophores. Conidial chains adhere into 

 close, compact cokimns which retain their general form even in fluid 

 mounts. The columnar nature of the spore masses results in large measure 

 from the incurved character of the metulae. The species doubtfully be- 

 longs with the other members of this series, but we believe that it will be 

 found here more readily than elsewhere. 



Whereas strains of Pcnicilliimi islandicum and, we believe, P. piceum, 

 are comparatively stable in laboratory culture, most of the members of this 

 series are extremely variable and unusually inconstant. Thus it is often 

 difficult to satisfactorily assign a given culture to some particular species. 

 Generally, this is more annoying than serious, however, for placement in 

 the series is usually sufficiently accurate for most studies. The funiculose 

 character of the surface growth, together with the characteristic pattern 

 of the conidial structure should enable the investigator to go this far with- 

 out difficulty. 



Penicillium funiculosum Thorn, in U. S. Dept. Agr., Bur. Anim. Ind., Bui. 

 118, p. 69, fig. 27. 1910. The Penicillia, pp. 464-465, 



fig. 77. 1930. 



Colonies on Czapek's solution agar spreading broadly in most strains, 

 commonly 4.5 to 5.5 cm. in 12 to 14 days at room temperature, consisting 

 of a fairly tough basal felt, usually with aerial growth loose-textured and 

 varying in depth up to 2 to 3 mm., in most strains showing aerial ropes of 

 hyphae (figs. 159A and 159C), often large and conspicuous and commonly 

 dominating the colony appearance, in others more or less tufted, especially 

 in central colony areas, and in still others essentially floccose with ropiness 

 evident but strongly reduced; variable in color depending upon the relative 

 amounts of vegetative mycelium and conidial structures and the pigmenta- 

 tion of the underlying agar, in some strains white to pink or flesh shades, 

 in others developing yellow to orange or red colors with some encrustment 

 of aerial hyphae; sporulating irregularly, often heaviest in central and 

 marginal colony areas, conidial areas varying in color, usually in yellow- 

 green shades from pea green through sage green to slate ohve (Ridgway, 

 PL XL VII) or deep grape green to Lincoln green (R., PI. XLI), but with 

 colors of conidial areas often altered or obscured by pigmented hyphae; 

 exudate lacking or limited in amount, clear or lightly colored; odor lacking 

 or mild, slightly earthy; reverse variable from flesh through pink to deep 

 red, or in some strains orange-brown, usually deeper under areas of heaviest 

 conidial development; conidiophores arising mainly at right angles from 

 funiculose hyphae, often very short, in marginal areas sometimes arising 

 directly from the substratum, ranging from 100 to 300m long by 2.5 to 3.0 



