284 BOTANICAL GAZETTE [april 



studies in this group. Moreover, the number of species included 

 in the Rhizinaceae is not large, and collections of some of these 

 are rarely made (Underwood 29, Hone 22, Burt 6). 



During the summer of 19 14 the writer discovered an abundant 

 supply of the apothecia of Rhizina undulata, and was able to collect 

 numerous very young fruit bodies in addition to the older stages. 

 These have furnished all the necessary material for a thorough 

 study of the development of the fruit body in this species. Rhizina 

 undulata is particularly suitable for investigation, since it is the 

 type of the genus and family, and probably the best known mem- 

 ber of the group. 



Schroter (27) separates the Rhizinaceae from the Geoglossaceae 

 and Helvellaceae on the basis of the sessile fruit body. Boudier 

 (3), attempting to arrange the Discomycetes in a natural classi- 

 fication, has developed a system very different from that of 

 Schroter. He makes his primary separation on the basis of the 

 method of rupture of the ascus. He places in one large group 

 (Opercules) those forms whose asci open by an apical lid, and in 

 the other group (Inopercules) those whose asci open merely by a 

 pore. By this separation the Helvellaceae and Rhizinaceae fall 

 in the first group and the Geoglossaceae in the second. Boudier 

 regards the Rhizinaceae as more closely related to such genera as 

 Peziza, Aleuria, and Sarcoscypha of the Pezizales than to either 

 the Helvellaceae or Geoglossaceae. Lagarde (23) makes the 

 primary separation also on the method of rupture of the ascus. 



The facts brought out in the study of the development of the 

 fruit body in various genera of the Discomycetes are especially 

 interesting for the bearing they have on the questions involved in 

 these two opposing systems of classification. The present inves- 

 tigation is undertaken with the hope that more complete infor- 

 mation with reference to ontogeny will render less difficult the 

 consideration of the phylogeny of the group. 



Rhizina undulata Fr. 



Historical. 



( 



in 1815. 



prominent 



celium, termed rhizoids. These are developed 



