HISTORICAL 11 



little more than guesses. Such species and varieties will be found only in 

 the Species Index (Chapter XVIII). 



Following Brefeld's work, Zukal, in 1889, described Penicillium luieum 

 as an ascosporic form with the unmistakable conidial apparatus of a bi- 

 verticillately symmetrical Penicillium. Asci were borne throughout a 

 loose network of hyphae almost if not completely lacking a perithecial 

 wall. From that description, Saccardo, without examining material 

 (Sylloge 11: 437. 1895), transferred the species to Gymnoascus, as G. 

 luteus (Zukal) Saccardo. Zukal described elliptical ascospores ornamented 

 with a spiral band passing 2 to 3 times around the cells. Wehmer (1893) 

 clearly illustrated the same type of spore. For many years thereafter no 

 one found such an organism in culture, although many related organisms 

 were collected. Derx (1925-1926) reported having had one. Professor 

 Bisby sent one to us from Manitoba in 1933, which was included in 

 Emmons' study of the ascocarps in Penicillium (1935). One or two 

 others have been seen. Subsequent to Zukal's description of P. luteum, 

 other workers, including Klocker (1903), Dangeard (1907), Thorn and 

 Turesson (1915), Lehman (1920), Emmons (1935), Swift (1932), and 

 Raper and Fennell (1948), reported a number of ascosporic Penicillia 

 showing the general series characteristics of Zukal's species but differing 

 in specific details. 



Examination of organisms identified as species of Gymnoascus reveals 

 ascogenous structures closely related to the Penicillium luieum series. 

 Detailed search through colonies of certain species of Gymnoascus dis- 

 closes very simple penicilli consisting of short conidiophores and groups of 

 one, two, or rarely more sterigmata bearing chains of conidia. One is 

 compelled to believe that Penicillium and Gymnoascus come very close to 

 each other, morphologically, in the P. luteum series. 



In another series, typified b}^ Penicillium javanicum van Beyma (1929), 

 the perithecium first develops as a pseudoparenchymatous mass of poly- 

 hedral, thick-walled cells at the center of which an ascogenous core sub- 

 sequently arises, and by enlargement gradually comes to occupy the entire 

 body except for a firm wall or peridium few to several cells in thiclaiess. 

 Other monoverticillate species with perithecia of this same general charac- 

 ter have been described by Klebahn (1930), Dodge (1933), and Raper and 

 Fennell (1948). The same process of perithecial development occurs in 

 the Carpenteles series noted above, but the penicilli in these latter forms 

 are typically biverticillate and asymmetrical, and the forms are placed in 

 the Divaricata. 



Langeron (1922), on purely bibliographic grounds, created the genus 

 Carpenteles for Brefeld's Penicillium glaucum, but since he studied no 

 cultural material the genus went unaccepted until Shear (1934) attached it 



