General Features 21 



would have a tendency to accelerate the force with which the 

 spore is ejected or " snapped out " of the ascus just as a seed 

 of a citrous fruit may be snapped from between the fingers by 

 bringing them quickly and tightly together. There must be a 

 contraction between each spore ejection, the ascus operating like 

 a machine-gun. 



Another point that might be mentioned here is the fact that 

 in all of these forms the spores are not only fusoid, but unequal- 

 sided. Since they do not always lie in the same position in 

 the ascus, this would have a tendency to throw the spores in 

 different directions, which would be a decided advantage, as 

 these particular forms have large, heavy spores as compared with 

 other species of the group and would not be so easily blown 

 about by the wind. While these latter facts seem to have no 

 particular bearing on the eccentricity of the ascostome they are 

 mentioned here because they have been noted in connection with 



that character. 



12. Asexual Reproduction 



While asexual spores have been reported for a few species of 

 operculate cup-fungi, such as Peziza vesiculosa and Peziza 

 repanda, on the whole this type of reproduction is conspicuous by 

 its absence in many of the species of this group, or, at least, has 

 not been observed. Plants of this section are in marked contrast 

 to some of those of the Inoperculates such as Sclerotinia in which 

 the reproduction by means of asexual spores has been developed 

 to a very high degree. So far as Sclerotinia is concerned, this 

 may be an adaptation to the parasitic habits of the plants of 

 the genus, the conidia functioning as repeating spores for the 

 rapid dissemination of the fungus while its host is in a susceptible 

 stage. 



The botryoide type of asexual spores has been reported by 

 Dodge for one species of the present group, Patella ahundans 

 (Fig. 12). This is a sui prise since this type of conidia is charac- 

 teristic of one section of the species of Sclerotinia, a genus which 

 in every other character is absolutely unrelated to Patella. 

 Perhaps careful search will reveal asexual spores in cases where 

 they have not been suspected up to the present time. 



Since several of the operculate cup-fungi in which conidia 

 have been found are heterothallic, it has been suggested that in 

 this group the conidia are especially adapted to facilitate the 

 bringing together of the plus and minus strains, thereby in- 



