Fig. 62. Conidial structures in the Aspergillus niger group, X 500: A, A. niger, 

 NRRL No. 326, typical head showing globose vesicle and primary sterigmata about 

 twice the length of secondaries; B, A. phoenicis, NRRL No. 1956, characterized by 

 long and occasionally septate primary sterigmata; C, A. carbonarius, NRRL No. 

 369, characterized by la^rge primary sterigmata and large conidia; D, A. violaceo- 

 fuscus, NRRL No. 360, characterized by small heads and sterigmata in a single series. 



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