ASYMMETRICA-VELUTINA 361 



XLII) after two or three weeks, in others ranging from celandine green 

 through artemisia green to Hly green (R., PL XLVII) or deep bluish gray- 

 green (R., PI. XLII) ; exudate abundantly produced in most strains, collect- 

 ing as conspicuous droplets (fig. 95A), in light to citrine yellow shades; odor 

 lacking or indefinite; reverse bright yellow near strontian yellow (R., PL 

 XVI) to dull yellow shades near olive-yellow (R., PL XXX), with surround- 

 ing agar usually colored throughout in lighter tints of the same shades. 

 Conidiophores arising primarily from the substratum in a dense stand, 

 variable in length, commonly up to 150 to 350m or more in length by 3.0 to 

 3.5m in diameter, with walls smooth and colorless; penicilli biverticillate 

 and asymmetrical, commonly showing one or more branches in addition to 

 the main axis (fig. 94B) terminating in verticils of 2 to 5 metulae bearing 

 sterigmata; conidial chains usually in well-defined columns commonly up 

 to 200m in length (fig. 94A and 95D) ; branches variable, commonly 15 to 

 25m in length by 3.0 to 3.5m in diameter; metulae usually 10 to 12m by 2 to 

 3m, occasionally longer; sterigmata in fairly compact verticils of 4 to 6, 

 mostly 8 to 10m by 2.0 to 2.5m but variable in different strains, with co- 

 nidium-bearing tips somewhat narrowed; conidia elliptical, rarely sub- 

 globose, mostly 3.0 to 4.0m by 2.8 to 3.5m, occasionally larger, smooth- 

 walled, yellowish green in mass. 



Colonies on steep agar growing more rapidly, 5.5 to 6.0 cm. in 10 to 12 

 days, strictly velvety, with conspicuous radial furrows, heavily sporing 

 throughout except for a narrow white to yellowish growing margin 1 to 

 2 mm. wide, conidial areas showing th^ same colors as on Czapek's agar; 

 exudate as described above but often more abundant; reverse in yellow 

 shades, usually somewhat duller than on Czapek; conidial structures as 

 described above but with columns often longer up to 300m or more. 



Colonies on malt agar, 5.5 to 6.0 cm. in 10 to 12 days, plane (fig. 95B 

 and F), never furrowed, strictly velvety, conidial areas showing the same 

 colors as above; exudate lacking; reverse in dull yellowish shades; conidial 

 structures as described above. 



Species diagnosis centered upon Thom's description based on the type 

 strain, NRRL 807 (Thom's No. 26), and upon comparative examination 

 in culture of many additional strains presenting the same basic cultural and 

 morphological characteristics. Strains now contained in our Collection 

 which are regarded as typical of the species include: NRRL 812, received 

 in 1940 from Professor H. Hotson, University of Washington, Seattle, as 

 an isolate from a 4 per cent iron-alum solution; NRRL 1186, received in 

 1940 from Dr. G. A. Ledingham, Ottawa, Canada as an isolate from meat 

 brine; XRRL 838, received in 1931 from Professor A. W. Henry, Univer- 

 sity of Alberta, Edmonton, Canada; NRRL 811, received in 1921 from 

 Dr. J. H. Birkinshaw, Nobels Explosives Co., Ayrshire, Scotland as an 



