OBSERVATION AND DESCRIPTION OF PENICILLIA 



31 



B 



Fig. 3. Types of colony surface and margin, 

 marginal area of a typical velvety colony, X 9.0. 

 area of a typical lanose colony, X 20. 



A, Petiicilliiim chrysogenum Thorn, 



B, P. caseicolum Bainier, marginal 



when growth ceases the fruiting area commonly extends to the very edge 



of the colony with conidiophores commonly arising from the substratum. 



Velvety and floccose colonies are sharply differentiated in their extreme 



