18 



The North American Cup-Fungi 



account for the eccentricity of the ascostome. He beheves that 

 the phenomenon is heh'otropic and that it will vary in the same 

 species with the direction of the light. Following this theory, 

 those species with deep cups in which the asci stand at an angle 

 of 45 degrees, the operculum would be developed on the up- 

 per side of the ascus in order that the spores might be directed 

 upwards instead of being shot across to the other side of the cup. 

 So far as the observations of the writer are concerned, there 

 appears to be no relation between the depth of the cup and the 

 eccentricity of the operculum and ascostome, since the latter 

 character has been found to be very constant in species belonging 

 to certain genera without regard to the form of the cup. A fine 

 example of this is afforded in PhiUipsia Chardoniana illustrated 



Fig. 9. Eccentricity of the ascostomes in PhiUipsia Chardoniana, 

 shown on the frontispiece. 



in the frontispiece of this work. In this species the apothecia 

 are as flat as a pancake yet, so far as observed, the ascostomes 

 are always eccentric or, at least, they are conspicuously and 

 predominantly so (Fig. 9). 



Another species in which the eccentric ascostome has been 

 especially observed is Cookeina Colensoi, a shallow cup which 

 occurs on wood in the tropics. So far as observed, the ascostome 

 in this species is always located decidedly on one side and is 

 unusually small compared with the size of the spores so that 

 there must be a good deal of stretching when the spores are 

 discharged through it (Fig. 10). 



Having noted this character in various species of PhiUipsia 

 and Cookeina and recalling that both of these genera have much 

 in common with the genus Wynnea, species of this latter genus 

 were examined and the same conditions found to exist (Fig. 11). 

 In all of these cases, however, it was necessary to work with 



