1920] DUFF—GEOGLOSSACEAE 345 



some 



and each is provided with these remarkable setae. In matters of 

 sexuality Trichoglossum appears to be still more reduced than 

 Spathitlaria. Ascogenous hyphae arise from threads which are 

 little if at all differentiated from the vegetative hyphae. 



Although Dittrich (Joe. cit) claims for Leotia lubrica the 

 possession of a veil in its younger stages, Brown (Joe. cit.), in his 

 more recent paper on this species, makes no mention of the occur- 

 rence of any such structure, and apparently has observed none. 



memum 



m 



examination of this form. Younger stages which show this 

 covering have not been found, however, so that considerable 

 uncertainty obtains with regard to the identity of this tissue with 

 that figured by Dittrich. 



A point of very great interest in this investigation is the close 

 resemblance of the conditions described for these Geoglossaceae 

 to those which Nienburg attributes to the C ladonia-like lichens 

 Icmadophila, Sphyridium, and Baeomyces. The occurrence in these 



already been mentioned. These carpogonia 

 with trichogynes in Icmadopkila; but they ai 



carpogonia 



Sphyrid 



IEN 



similarity include the occurrence 



in the early stages, and the methods of ascus formation. This 

 remarkable parallelism evidently represents a relationship. Al- 

 though a general relationship between the Ascolichens and other 

 ascomycete groups, such as the Discomycetes and Pyrenomycetes, 

 has long been recognized, and although some lichenologists have 

 advocated and attempted the distribution of the lichen genera 

 among those of other Ascomycetes, a fundamental basis of relation- 

 ship between the discolichens and the order Helvellineae has been 

 wanting. This basis is supplied here and consists of a close 

 similarity in developmental history, particularly with regard to 

 the veil and to the manner and time of appearance, number, 

 position, and condition of procarps. As our knowledge of these 



