272 A MANUAL OF THE PENICILLIA 



Davidson, Division of Forest Pathology, U. S. Department of Agriculture, 

 as an unidentified ascosporic Penicillium, differs from the above in pro- 

 ducing colonies with fewer conidial structures, more abundant perithecia 

 upon all media, and ascospores that appear less conspicuously ridged than 

 those of the type strain. The culture, however, may be regarded as typi- 

 cal of the species. 



Our observations are generally in close agreement with van Beyma's 

 and the species diagnosis presented above differs little from the original 

 description. 



The type culture was isolated from soil in 1932 by Professor Y. S. 

 Sabet at Cairo, Egypt, and was submitted to van Beyma who described 

 the form as a new species, PeniciUium egyptiacum (1933). Two additional 

 isolations were made from Egyptian soil by Sabet (1935). The species 

 has been isolated by other workers since that time and is believed to be 

 cosmopolitan in distribution. AVhen first isolated, the type produced peri- 

 thecia very abundantly. Sabet (1936) reported a tendency toward the de- 

 velopment of sectors marked by increased conidium and reduced perithe- 

 cium formation and succeeded in separating out a sub-strain which was 

 predominantly conidial and showed only a feeble capacity to form perithe- 

 cia. During the period that the type has been maintained in artificial 

 culture, both at Baarn and in our laboratory, it has become predominantly 

 conidial but still retains the capacity to produce fertile perithecia. By 

 selective recultivation in the present study we have succeeded in reiso- 

 lating a predominantly perithecial strain which apparently closely approx- 

 imates the type in its original form. NRRL 716, maintained in laboratory 

 culture since 1934, has consistently produced abundant perithecia. 



The perithecia of PeniciUium egyptiacum strongly resemble those of the 

 P. javanicum series in the Monoverticillata both in initial structure and in 

 the manner in which they mature. The penicilli, however, are typically 

 biverticillately asymmetric with monoverticillate penicilli present but 

 obviously representing reduced structures. The perithecium ripens from 

 the center outward by the development of a network of fertile hyphae 

 which gradually replaces the parenchymatous to somewhat sclerotioid 

 tissue. Asci are borne in chains, and develop more quickly and more 

 abundantly than in either P. baamense or P. asperum. 



Occurrence and Signijicance 



Members of the so-called Carpenteles series are known only as isolates 

 from soil where they appear to be widely but not abundantly distributed. 

 Their possible role in microbiological processes in nature is unknown. 

 They are of interest primarily because of their ascosporic phase. 



