18 HUMPHREY 
In many cases a complex of hyphe over-runs the surface of a 
leaf and it is not uncommon to find chlamydospores in connection 
with these external hyphz. One-celled conidia are abstricted 
in large numbers from branches of the external hyphe. Sclerotia 
have not yet been found, though occasionally a cell may be seen 
well filled with knots of hyphez, too loose in structure, however, 
to be regarded as sclerotia. Cells in which these knots occur 
are always dead and apparently empty. 
The fungus behaves toward the host as a parasite. Its hyphe 
produce haustoria in great numbers which in the course of time 
invade all the cells of a leaf, thus impairing greatly its ability to 
elaborate food materials. The younger leaves of the host are 
apparently uninfected, and even though the older parts of the 
thallus may be dead, growth continues at the growing point and 
the plant may grow indefinitely, though very evidently diseased. © 
The writer has not thus far observed a fungus associated with 
our species of Spherocarpus or with Targionia hypophylla, 
although Golenkin’ reports the existence of an endotrophic 
mycorrhiza for the latter, and it may be that further investigation 
will demonstrate the presence of a fungus in Zargzonza as we 
find it here. Asa matter of fact it is not improbable that all 
the hepatice of this region may on further study prove to be 
- infected, the fungus being either a symbiont or, what is more 
likely, a parasite. The writer has seen no evidence in favor of 
the view that the fungus stimulates the growth or in any way 
benefits the host, though the presence of hyphe may lead up to 
the development of abnormal structures such as modified root- 
hairs, enlarged cells, etc. 
Bruchmann,’ in his studies on Botrychium lunarza, concludes 
as follows: ‘* Der physiologische Nutzen des Zusammenlebens 
von Prothallium und Pilz scheint mir auch hier nicht darin zu 
bestehen, dass die wenigen und unscheinbaren Pilzfaden, 
welche aus dem Substrat des Gamophyten in ihn emmiinden, 
belanglose Humusstoffe ihm zufiithren, Sondern nur darin, 
dass die von den functionsfahigen Rhizoiden der wachsenden 
Schutelpartie aufgelésten und herbeigeftihrten Baustoffe mit- 
THSOE. Cit, 4p. 209s 
aoc. iCit. 
