124 A MANUAL OF THE ASPERGILLI 



6.5/x by 2.5 to 3.5^; conidia finely spinulose, subglobose, variable in size, 

 ranging from 3.5 to 5.2/u mostly about 4/x in long axis. 



Represented in the XRRL collection by cultures Xos. 89, 90, and many 

 others. 



Thirty-two cultures belonging to this series have been examined in the 

 present study. Included in this number are the authors' own isolates from 

 a wide variety of sources together with cultures contributed by collabora- 

 tors in this country and abroad. Of these, more than three-fourths regu- 

 larly produce colonies conforming with the above description of the species 

 A. amstclodami. Although wide variation in colony character does occur 

 within the series, it is obvious that such variations are exceptional rather 

 than commonplace. Accordingly, it is not believed advisable to assign or 

 create specific or varietal names for these variations although they differ 

 markedly from the typical A. amstclodami in gross appearance. An excep- 

 tion to this policy has been made in the case, of cultures received as A. 

 montevidcnsis, for reasons that will be considered later. 



As indicated in the preceding key to the series, marked variation from 

 the normal cultural character of .4. amstclodami occurs along certain diver- 

 gent lines. 



Culture XRRL Xo. 113 (fig. 32 B) received from Baarn as Eurotium 

 repcns (Cda.) DeBary and Wor. var. amstclodami Vuill. (1920) represents 

 a variation that tends toward an almost complete suppression of the conidial 

 phase with only an occasional small and atypical head present. 



In the opposite direction, culture XRRL Xo. Ill (fig. 32 C) recently 

 received from Bliss in California (isolated from date fruits) represents a 

 variation that produces a dense stand of conidial heads and only occasional 

 perithecia, these being borne above rather than below the layer of crowded 

 conidial heads. 



In contrast to both of the preceding, culture XRRL Xo. 110 isolated 

 from an old shoe, produces an extremely thin, spreading colony that bears 

 only widely scattered perithecia or conidial heads. 



A fourth distinct variation is represented by culture XRRL Xo. 108 

 received in 1932 from Talice as A. montevidcnsis Talice and MacKinnon 

 (1931). This fungus is characterized by an initially strong development of 

 the conidial phase, and subsequently of perithecia in a felted overgrowth, 

 which in the colony center more or less obscures the underlying conidial 

 layer. Perithecia and conidial heads are somewhat smaller than in strains 

 of A. amstclodami. Although this culture does not differ from ^4. amstelo- 

 dami more widely than the variations previously noted, since it has an im- 

 puted pathogenic history and since it has been described and distributed 

 widely under the name Aspergillus montevidcnsis, it is believed advisable 

 to retain the name in association with this culture. Accordingly, the 

 writers include the following emended description. 



