PHYSIOLOGY AND MORPHOLOGY OF CALIFORNIA HEPATIC^ II 



Others yet free from the fungus, but it is owing to the fact that 

 the degree of infection is but slight and the vigor of the host 

 is sufficient to throw off for a time the harmful effects of the 

 parasite just as the leaves of cultivated lettuce maintain apparent 

 full vigor during early stages of the infection by Bremta 

 lactiica} 



Experiments designed to ascertain the effect of the fungus 

 upon very young plants of either Fossomb}-onia or Fimbriai'ia 

 have thus far failed, and it cannot be decisively stated here that 

 Fimbriaria is at all susceptible to infection by this fungus. The 

 examination of a large number of plants of all stages of develop- 

 ment has shown our common species, F. californica, compara- 

 tively free from infection b}'- any fungus. Recently, however, 

 the author has found a few plants of this species attacked by a 

 fungus which seems, in material thus far examined, to be con- 

 fined entirely to the cells of the first four layers on the ventral 

 side of the thallus. H3^ph£e in considerable numbers were ob- 

 served in both the smooth and tuberculate rhizoids. These 

 showed but slight tendency toward branching, in many instances 

 extending the entire length of a rhizoid without producing a 

 branch. The hyphas confined to the rhizoids, compared with 

 those within the mycorrhizal zone of the thallus, are very much 

 more delicate ; but upon extending into the cells of the thallus 

 they branch profusely and develop relatively thick and tough 

 walls. The fungus resembles the one described above for Fos- 

 sonibrotiia, in that it is filamentous and septate. Structures com- 

 parable to vesicles, conidia or sclerotia have not yet been 

 observed. The presence of the fungus seems in no wise to re- 

 tard the growth or affect the vigor of the thallus and no plants 

 have yet been found in which the hyphae have penetrated the 

 chlorophyll-bearing tissue. 



THE PARASITIC FUNGUS ASSOCIATED WITH ANEURA 

 MULTIFIDA MAJOR. 



While in the field collecting Aneiira the writer observed that 

 a considerable number of plants had taken on a rusty brown 



'An illuminating discussion of symbiosis and parasitism is to be found in 

 Plant Physiology. Peirce. Pp. 85-92 inclusive. 



