PEN K'll.I.ir.M (HRYSOGEN I'M. 



59 



The culture here named P. chrysogenum has been kept under 

 observation for more than four years without change. In this time 

 several forms have been collected or sent to this Laboratory which 

 also produce the golden color in the digestion of milk suggestive of 



the name proposed. The cultural characters of these races differ 



in some degree in several eases, in others substantial identity has 

 been observed. In reporting cultural data three numbers are 



included for Comparison with this, viz, Nos. l'">, 35, and II. These 



agree in the following characters: Spreading habit, surface mostly 



l [Q 20.— Penicillium chrysogenum: a, l>, e, d, >, branching of conidial fructification from gelatin plates 

 (X 900); /, g, I'.j. I. m, sketches of conidial fructifications from potato-agar plates 140); n, o, germination 

 ofconidi . 



of conidiophores averaging about 300/f in length, nearly the same 

 shade of green in color, similar morphology of conidial fructification, 

 digestion of milk, gelatin, etc., with the production of yellow or 

 golden color, liquefaction of gelatin progressive but slower than the 

 expansion of the colony in the subsl ratum so that a gro^ in r border 

 of submerged vegetative hyphffl extends into hard gelatin for con- 

 siderable time, in contrast to forms in which the colony becomes a 

 floating "island" in a pool of fluid within the first week. In spite 

 of these common characters colonies of these four races often show 



