THE ASPERGILLUS NIDULANS GROUP 



159 



having a firm almost sclerotioid wall, whereas the wall is found to contain 

 but one laj^er of cells. He figured the asci as few and scattered in a mycelial 

 matrix within which ascospore production occupied many weeks. One 

 isolated strain in our collection produces asci in this manner. For it, the 

 varietal name, A. nidulans var. latus, was proposed by Thorn and Raper 

 (1939) on account of very broad crests on the ascospore in contrast to the 

 usual types in A. nidulans which come much more closely to those indicated 

 in Eidam's figures. 



TABLE 1 

 Ascospore variation in strains of Aspergillus nidulans 



Culture number 



NRRL 193.. 

 NRRL 188. . 

 NRRL 189.. 

 NRRL 194.. 

 NRRL 195*. 

 NRRL 191 . . 

 NRRL 187.. 

 NRRL 192.. 

 NRRL 198. . 

 NRRL 199.. 



Overall dimension of spores 



6.2-6.6 

 6.0-6.6 

 6.0-6.4 

 5.4-5.8 

 5.4-5.8 

 5.4-5.8 

 5.4-5.8 

 5.0-5.4 

 4.8-5.4 

 4.8-5.2 



x 3. 6-3. 8 M 

 x 3. 6-3. 9/x 

 x 3. 6-3. 8m 

 x 3. 6-3. 8m 

 x 3. 6-3. 8m 

 x 3. 6-3. 9m 

 x 3. 6-3. 8m 

 x 3. 6-3. 8m 

 x 3. 6-3. 8m 

 x 3. 6-3. 8m 



Dimensions of spore bodies 



4.2-4.6 x 3. 6-3. 8m 

 4.0-4.6 x 3. 6-3. 9m 

 4.0-4.4 x 3. 6-3. 8m 

 4.0-4.4 x 3. 6-3. 8m 

 4.0-4.4 x 3. 6-3. 8m 

 4.0-4.4 x 3. 6-3. 9m 

 3.9-4.3 x 3. 6-3. 8m 

 4.0-4.4 x 3. 6-3. 8m 

 3.8-4.4 x 3. 6-3. 8m 

 3.8-4.2 x 3.6-3. 8m 



* White mutant from culture NRRL No. 194; described by Yuill as Aspergillus 

 nidulans mut. alba. 



A. nidulans mut. alba Yuill, in Jour, of Botany (London) 



175, pi. 618. 1939. 



Colonies of the variety on Czapek's solution agar differ from the species 

 in the entire absence of green color (fig. 41 B). The ascospores have the 

 characters of the species. 



Culture obtained by Yuill as a mutant from a normal green strain of A. 

 nidulans under investigation in his laboratory. Our record number is 

 NRRL 195; the normal and parent strain is NRRL 194. 



Aspergillus nidulans var. latus Thorn and Raper. Mycologia 31 : 657. 1939. 



Colonies on Czapek's solution agar differing from the species in colony 

 development characterized by a felt of predominantly sterile mycelium; 

 few conidial heads; fairly abundant perithecia developed in the mycelial felt 

 and each surrounded by a thick covering of hlille cells (fig. 42 C), very slowly 

 ripening and containing few and scattered asci in abundant sterile mycelium. 

 Ascospore bodies smooth-walled, purple-red, 3.8 to 4.5m by 3.5 to 4m, with 

 crests 1.5 to 1.8m in width. 



Type culture NRRL No. 200 received from the Centraalbureau in 1909 

 and remaining constant in culture since that time. Its antecedent history 

 is not known. 



