CHAPTER XV 

 SAC FUNGI IN PARTICULAR (YEASTS, ETC.) 



Suborder A. Protoasciineae.— The fungi of this suborder are charac- 

 terized by the absence of definite fruit bodies, that is the asci are not 

 enclosed, but are free and at the ends of hyphae. Usually they are of 

 unequal length. Four is the typical number of ascospores in each 

 ascus. These are one-celled and may increase in number by gemmation. 



Family i. Endomycetace^. — This family is a small one of four 

 genera of saprophytes and parasites. The two species of the genus 

 Podocapsa are parasitic on Mucorace^, Eremascus albus, the single 

 species of that genus grows on spoilt malt extract. The genus En- 

 domyces with five species is represented by the cosmopolitan Endo- 

 myces decipiens, which forms a snow-white parasitic growth on the 

 toadstool Armillaria meltea. Its hyphae are branched richly and the 

 asci are pear-shaped and borne singly at the ends of the branches, 

 each producing four helmet-shaped ascospores, 6 to S/jl broad and s^u 

 high. Conidiospores are more frequently foimed than ascospores. 

 Oidiospores are also found, as well, as chlamydospores. Oleina nodosa 

 and O. lateralis are the two species of the fourth genus. The first 

 grows in ohve oil. 



Family 2. ExoASCACEifc.— This family includes parasitic fungi 

 which cause abnormalities of more or less marked character of the 

 leaves, fruits and branches of mostly woody plants. The malforma- 

 tions are in the nature of witches' brooms of the smaller branches, 

 leaf curls, and deformed fruits, such as the plum pocket. Stone fruits 

 are especially subject to attack and in some cases the stone formation 

 is suppressed entirely. The myceUum may be deep-seated and 

 perennial, or it may be subcuticular, or sometimes found growing 

 between the epidermal cells, as in Magnusiella flava, while in other 

 forms, the hyphae may be below the epidermis and grow throughout 

 the leaf tissue. The asci are generally formed on the surface of the 

 host breaking through from the more deep-seated mycehum beneath. 

 They are generally stalkless and arranged in close proximity to each 



131 



