190 BOTANICAL GAZETTE [September 



are the rhizoids as deformed by the fungus as by the obstacles in 

 their path of growth. 



Inoculations of pure cultures have not been made because of the 

 desire to get as many sporelings as possible to develop mature thalli. 

 Some of the fungi obtained pure were a species of Fusarium, Cepha- 

 lothecum roseum, a species of Alternaria and of Gloeosporium, and an 

 unidentified one which grew with Pencillium in an impure culture. 

 Gar jeanne has found that more than one species may be present 

 at the same time in a rhizoid. It will be interesting to know how 

 many of the above can infect the spores. 



Summary 



1. The gametophyte of Aneura pinguis is a simple, slightly 

 differentiated thallus. 



2. Archegonia and antheridia are borne on lateral branches of 

 dioecious plants; they develop according to the J ungermannia type. 



3. The sporophyte of Aneura pinguis is highly specialized. 

 One-half of the embryo at its first division forms a haustorial cell; 

 from the other half capsule, seta, and a temporary foot develop. 

 Sterilization of the tissue of the capsule occurs at three periods: 

 (1) the wall and apical cushion are cut out; (2) the elaterophore is 

 defined; (3) sporogenous tissue is differentiated into elaters and 

 spore mother cells. 



4. The capsule splits by four early defined valves. The spores 



chloroplasts at maturity 



tonemal 



The 



spore coat incloses the very young sporeling. 



mature 



some 



Infection takes 

 taere. Rhizoids 



may be infected from the thallus. 



7. No gemmae are found on Aneura pinguis. New plants are 

 produced by the dying back of the old thallus. 



Acknowledgments are due Professor John M. Coulter and 

 Professor W. J. G. Land, under whose direction this work was done. 



The University of Chicago 



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