PHYSIOLOGY AND MORPHOLOGY OF CALIFORNIA HEPATIC^ 5 



In a few instances infected rhizoids were found to have under- 

 gone considerable modification of form as seen in Fig. 5. On 

 the other hand very similar modifications were repeatedly ob- 

 served in uninfected rhizoids. These were very likely due to 

 the stimulus of contact with compact soil. Whether the fungus 

 is instrumental in the development of such malformations as the 

 one shown in Fig. 5 cannot be determined at this writing. It 

 is, however, hardly probable, for the writer has observed that 

 when infected plants are transferred to Knop's solution the new 

 rhizoids though seriously infected maintain a uniform direction 

 of growth and are apparently unaffected by the hyph£e. 



In a previous paper ^ mention was made of the fact that Fos- 

 sofnbronia plants in many instances developed a tuberous growth 

 which, on careful examination, was found to contain a more or 

 less complex growth of fungus hyphae. Microchemical tests 

 demonstrated the presence of a large quantity of starch, oil and 

 nitrogenous food products within the cells of this tuberous 

 growth and this, no doubt, in a measure accounts for the greater 

 development of the fungus in this region. So far as the author 

 has observed, none of these tuberous growths is free from infec- 

 tion. It is hardly probable, however, that this structure is 

 directly due to the activity of the fungus for it is a structure 

 common to a number of other hepaticie such as Gcothalliis 

 tuberosus Campb., Riccia canccUata Tayl., Fossombronia tuber- 

 ifera Goebl., and a number of others in which no fungus infec- 

 tion has been observed. Specimens of Geoihallus tuberosus 

 have been carefully examined by the writer with a view to 

 ascertaining the presence of infection, but in all material ex- 

 amined the tubers were uninfected and filled with reserve food 

 products as described by Campbell,- '95. No doubt the tuber 

 in the case of Fossombronia longiseta serves the same purpose 

 as in Geothallus tuberosus or in Fossombronia tubcrifcra^ i. <?., 

 as a special structure to carr}'- the plant through a more or less 

 prolonged dry season. Howe^ has shown that in specimens of 



^ Loc. cit. 



"Campbell, 1896: A New California Liverwort. Botanical Gazette, Vol. 21, 

 No. I, p. 12. 



^Howe, 1899: The Hepaticse and Anthocerotes of California. Memoirs of 

 the Torrey Botanical Club, Vol. VII, p. 80. 



