(388 a manual of the penicillia 



Paecilomyces 



Bainier, in 1907, established the genus Paecilomyces, with the type species 

 P. varioti, to cover a saprophytic mold lacking green color but producing 

 verticillately branched conidial structures superficially resembling those pro- 

 duced in Penicillium. His generic description as translated and emended 

 by Thorn in 1930 (p. 541) follows: 



"Genus related to Penicillium and Aspergillus, distinguished by sterigmata short- 

 tubular or more or less enlarged, tapering into long conidium-bearing tubes mostly 

 curved or bent slightly away from the axes of the main sterigmatic cells; sterigmata 

 variously arranged, partly in verticils and branching systems suggesting Penicillium, 

 partly irregularly arranged upon short branchlets, partly arising singly along the 

 fertile hyphae; conidia in chains, elliptical, never green." 



Thom, in 1910, described Penicillium divaricatum and subsequently ac- 

 cumulated a large series of closely related strains. Later Bainier's strain 

 of Paecilomyces varioti was received from Paris and easily seen to be iden- 

 tical although no one had reported its identification from Bainier's descrip- 

 tion. Paecilomyces was, therefore, accepted as the correct generic usage 

 in Thom's Monograph (1930, pp. 544-545). Home and Williamson (1923), 

 working with an organism of this group, described as "macrospores," large 

 cells which were borne mostly near, or just- below, the surface of the cul jur3 

 medium upon soHtary or variously aggregated branchlets from the fertile 

 hyphae. They regarded these macrospores as fixing the generic allocation 

 of the species and transferred it to Eidamia of Lindau (1907). These 

 accessory structures were previously known to Thom but were not dis- 

 cussed by either him or Bainier in their original descriptions. Thom, in 

 1930, figured such structures and noted their abundance in certain strains, 

 particularly in one which had come from Kita and Wai in Japan. Their 

 significance soon became apparent when Olliver and Smith (1933) dis- 

 covered a strain presenting the general morphology of P. varioti in all 

 respects except that these sterile cells, or "macrospores," developed into 

 individual asci and each produced eight smooth, hyaline, ovate ascospores 

 measuring 6.0 to 6.5/x by 4.3 to 4.5m. Olliver and Smith assigned their 

 ascosporic strain to Westling's genus Byssochlamys (1909) as a new species, 

 B. fidva. In discussing the genus Byssochlamys, Thom, in 1930, had ob- 

 served that the conidial apparatus of Westling's species suggested relation- 

 ship with Paecilomijces. Emmons, in his study of ascocarps of Penicillium 

 (1935), discussed the details of ascospore production and contrasted this 

 with the PenicilHa. WestUng regarded his genus Byssochlamys as inter- 

 mediate between the Endomycetaceae and the Gymoascaceae, a position 

 which it seems to fit quite well. 



Diligent search over a number of years has revealed few ascosporic 



