PHYSIOLOGY AND MORPHOLOGY OF CALIFORNIA HEPATICZ 39 
rains and rapid desiccation following one upon the other. What- 
ever be the cause of impairment the fact remains that almost 
no spores germinated even under most painstaking precautions 
as to culture conditions. To get at the root of the matter, how- 
ever, a series of experiments is necessary in which the student 
should duplicate as nearly as possible the conditions prevailing 
from April 1 to June 15 of 1906. 
It is an unsettled question as to whether the spores of many 
liverworts actually require a prolonged resting-period, and there 
is still need of investigation along this hne. We are familiar 
with the fact that the spores of most xerophilous forms do lie 
dormant several weeks before germinating but it has not been 
shown in very many instances that this resting-period is inti- 
mately connected with the preparation of the spore for germina- 
tion. The writer has demonstrated beyond doubt that the spores 
of Hossombronia longiseta, under certain conditions, do not re- 
quire a resting-period. Cultures were prepared using different 
media with a view to testing, if possible, the relative influences 
of the various media upon germination. One lot of spores col- 
lected on January 10, 1906, were sown January 12 on pulver- 
ized earth that had been thoroughly steam-sterilized and well 
watered with distilled water. Care was exercised to select soil 
on which Fossombronza grows vigorously out of doors; this 
was placed in a crystallization dish and covered with one half 
of a petri dish to keep the culture as free from dust as possible. 
A number of crystallization dishes were thoroughly cleaned 
and then covered on the inside with a thin coating of paraffin 
to prevent the water used from taking up any impurities that 
might exist in the glass. In three of these, Knop’s nutrient 
solution of the following proportions was placed: 
AO) ores oiht Yeia. closes cscs cisce sista waists isle eilaisjelaleitice 500 c.c 
SCM WILT ALC ccene deen deenine aelsdenealacaine eee 2.00 grams. 
MAS HeStUM SUL Mates. ce saccecascsseseoeroe 0.5 oe 
Potassium nitrate...... he cpocon pes ocwnoo00G8s 0.5 ie 
Porassiuim phosphates. vaccesecsscenascoasess 0.5 es 
Other solutions of varying strength were employed as follows : 
BOE steerer a dese vei dwihnseneivameees svceas estedans 500 c.c 
CAleMIMA METALS... < eee. calSonccpes nsec senases 2.00 grams. 
Masnesinin Sul phiatess.iscsscsncccucvecneses. 0.5 es 
POPaSSH IM MIEKALC .vocs,\cecccstubceses tess oslean Os “ 
Potassium phosphate omitted. 
