366 A MANUAL OF THE PENICILLIA 



3.3m less commonly 400 to SOO/i in length occasionally borne from aerial 

 hyphae and shorter, about 50 to 75m in length, apices somewhat inflated; 

 penicilli asymmetric, commonly branched, with branches and main axes 

 each usually bearing 2 to 4 metulae to form a fairly large conidial structure, 

 less commonly consisting of a simple terminal verticil of metulae only, with 

 conidial chains adherent into fairly well-defined columns up to 150m in 

 length, branches when present variable, from 10 to 20m by 2.0 to 3.0m; 

 metulae mostly 9 to 12m by 2.0 to 2.5m; sterigmata closely appressed, in 

 compact clusters of 6 to 8, about 7 to 9m by 1.8 to 2.2m; conidia elliptical, 

 3.0 to 3.5m by 2.5 to 3.0m, smooth-walled, light yellow-green. 



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

 12 days, comparatively loose-textured, velvety, conspicuously and closely 

 radiate in pattern, heavily sporing throughout, with conidial areas colored 

 as above; exudate abundant, clear or nearly so, in small droplets, with 

 craters resulting from evaporation appearing pinkish ; reverse in vinaceous 

 drab shades, penicilli as described above except conidiophores averaging 

 somewhat longer. 



Colonies on malt agar spreading broadly, about 6.0 to 6.5 cm. in 12 days, 

 plane (fig. 96B), strictly velvety, near Russian green (R., PI. XLII); no 

 exudate produced; reverse uncolored or in dull yellow shades; penicilli as 

 described above but with well-defined columns up to 200 to 250m in length. 



Species description centered upon NRRL 836, received in January 1929, 

 from J. H. Birkinshaw, Nobel Explosives Company, Ayrshire, Scotland 

 and discussed by Thorn (1930) under this name as No. 5034.53 in 1930; 

 NRRL 2136, received in September 1943, from Nancy Atkinson, Institu- 

 tion of ^Medical and Veterinary Science, Adelaide, Australia, as an unidenti- 

 fied Penicillium reported to produce an antibiotic similar to penicillin; and 

 a few additional cultures duplicating the above but not maintained in 

 our permanent collection. The species appears to represent a widely 

 distributed but fairly uncommon soil form. 



Tests conducted at this Laboratory show that cultures of the present 

 type produce limited amounts of penicillin. 



Biourge described Penicillium meleagrinum as characterized by an aerial 

 down and spotted colony reverse, presenting a guinea hen appearance, from 

 which character the name is derived. Thom (1930) recognized under this 

 name cultures obviously belonging to the P. chrysogenum series which 

 showed broad white growing margins, reddish, violaceous or drab colored 

 reverse, clear exudate, asymmetrical smooth-walled penicilli, and elliptical 

 smooth conidia 3.0 to 3.5 or 4.0m in long axis. Exact duplication of Bi- 

 ourge's species was not claimed, since his type had not been seen. In 

 neither exudate nor colony reverse does the species show the bright yellow 

 colors that are generally characteristic of the present series. Recognition 



