V] 



SPHAERIALES 



iSS 



Chaetoniiaceae 



The Chaetomiaceae occur on straw, paper, dung and other waste 

 materials; they possess free, thin-walled perithecia beset with numerous 

 characteristic, long hairs (fig. 112), which are often elaborately branched 

 or coiled. On these, or on the ordinary vegetative mycelium, conidia are 

 produced. An ostiole is lacking in Ch. fimete, presumably the most primitive 

 member of the genus; in the remaining species it is present and the peri- 

 thecium is of the typical sphaeriaceous form. 



In Chaetomium spirale the cells of the mycelium contain each a single 

 nucleus, the archicarp arises as a coiled branch and divides into four or 

 more uninucleate cells. There is no sign of an antheridium. Vegetative 

 hyphae grow up from the stalk of the archicarp, and from the filament on 

 which it is borne, and form a sheath, the outer cells of which are prolonged 

 as hairs. Small pyriform conidia are abundant. 



Ch. Kunzeanum shows a very similar archicarp (fig. 113), but here the 

 cells, as described by Vallory for the variety chloriimm, each contain several 

 nuclei which are often found approximated in pairs. This arrangement is 

 reported to be as common in the vegetative mycelium as in the cells of the 

 archicarp, and is doubtless a result of rapid division. 



112. Chaetomium pannosum'^iWc.; x 50 ; 

 W. Page del. 



Fig. 113. Chaetomium Kunzeanum 

 Zopf ; archicarps ; after Oltmanns. 



