EUASCOMYCETES 



111 



In many species, the conidia are bound together in chains by short 

 disjunctors (connectives). Brefeld (1874) regards this in his Penicil- 

 lium " crustaceum" as a section of the "sterigma." Thorn (1914; Thorn 

 and Church, 1926) considers that in Aspergillus the true, thick, round spore 

 wall has only arisen in the cells cut off from the phialides; in case these 

 original cells are not entirely filled out, the collapsed residue remains 

 hanging as a connective between the spores. According to some observa- 

 tions of the author on Penicilliopsis clavariaefonnis it is a question of papil- 

 liform arching at the base of the conidia whose function is still unknown. 



Fig. 111. — Penicilliopsis clavariaeformis. 1 to 3. Development of the eonidiophore. 

 Sp, germinated conidium. Penicilliopsis brasilie?isis. 4. Conidiophore with dimorphic 

 conidia. ( X 330; 1 to 3 original; 4 after Moller, 1901.) 



Under certain cultural conditions, as on substrates which contain 

 nitrogen in the form of nitrates, also by increased transpiration, by 

 lowering the oxygen tension of the air, in the presence of glycerol as a 

 carbon source, or in definite physical state of the substrate, the conidio- 

 phores of many species of Penicillium form coremia (Munk, 1912; 

 Wehmer, 1914; Boas, 1915, 1916). While these conidia (Fig. 110) in 

 true species of Penicillium form only as abnormalities, in some other 

 genera (by some authors regarded as subgenera of Penicillium), as in 

 Acaulium (Fig. 7, 2) and Stysanus (Fig. 7, 1), they have become the 

 rule and thus arise normally. In these genera there are beginnings of 

 conidial fructifications which we shall meet later in Isaria (imperfect 

 forms of Cordyceps) under the Hypocreaceae; thus a series of species 



