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 hyphe. 
In a previous paper’ mention was made of the fact that /os- 
sombronza plants in many instances developed a tuberous growth 
which, on careful examination, was found to contain a more or 
less complex growth of fungus hyphe. 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 hepatice such as Geothallus 
tuberosus Campb., Lezccza cancellata Tayl., Possombronta tuber- 
tfera Goebl., and a number of others in which no fungus infec- 
tion has been observed. Specimens of Geothallus 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 tuberifera, 7. é., 
as a special structure to carry the plant through a more or less 
prolonged dry season. Howe®* has shown that in specimens of 
EV oe, cit: 
Campbell, 1896: A New California Liverwort. Botanical Gazette, Vol. 21, 
Wo. kp i. 
? Howe, 1899: The Hepatice and Anthocerotes of California. Memoirs of 
the Torrey Botanical Club, Vol. VII, p. 8o. 
