PHYSIOLOGY AND MORPHOLOGY OF CALIFORNIA HEPATICZ 7 
hyphe, though the more compact tissue of the thallus was in 
many such instances thoroughly infected. Thus it would seem 
that infection need not necessarily take place through the rhi- 
zoids. Material carefully fixed in chromic acid (1 per cent.) 
and stained with the Fleming’s triple combination seemed to 
give very satisfactory results, though it was found necessary to 
allow more time to the action of the stain than was customary 
in staining organs or structures of the host. Sections through 
the stem of infected plants almost always showed a well-de- 
fined zone of cells more or less given over to hyphe. This is 
not unlike the condition observed by Cavers'* (03) in Fegatella 
and by Golenkin’ (02) in a number of forms cited above. 
Golenkin states that the cells of this zone, though still retaining 
their protoplasm and nuclei, are void of chlorophyll and starch. 
Careful examination of infected cells of Hossombronza, except 
where infection was so far advanced that the cells were occu- 
pied by developing sclerotia, revealed the presence of varying 
amounts of chlorophyll and starch, depending upon the number 
and vigor of invading hyphe. 
Unlike the forms described by Golenkin, this fungus is not 
necessarily confined to any given zone, for any portion of the 
thallus may be invaded by hyphz extending out from the more 
compact parts. ‘Though several hundred fruiting plants have 
been studied, no evidence of infection of either antheridium or 
archegonium has yet been seen, and the sporophyte is appar- 
ently free from the attack by fungus. 
In material fixed in January, 1904, about three months after 
the beginning of the rainy season, almost the entire tissue of the 
stem was packed with hyphe, many branches extending through 
the outer layer of cells of the host into the substratum. 
Although the fungus was present in virtually the whole of 
the stem-tissue, strictly speaking, it was found that at this stage 
of its development the hyphe were more or less confined to the 
innermost cells of the stem while those in proximity to the 
growing point as well as the leaves were apparently free from 
infection. The epidermal cells and those immediately beneath 
? Loe. cit. 02 33: 
* LOE; Cit... ps 200: 
