224 
GEORGE S. BRYAN 
chaetial leaves surrounding the organs. These well defined characters 
made field work a very simple and easy matter once they were determined. 
In the latter part of November and during December, 1912, a careful 
survey of the bog was made, the best polsters being staked out with serially 
numbered stakes : one series for polsters of plants bearing only archegonia ; 
another for those bearing only antheridia; and a third series for the areas 
in which the sexes were mixed together, where it was hoped to secure material 
for a study of fertilization. Notes on field and laboratory observations 
were kept, and from them the following facts are taken. 
By the end of November, 191 2, the weather had become very cold, the 
bog being frozen to the depth of several inches. Blocks of frozen plants 
together with the frozen mud on which they were growing were cut out with 
a hatchet and carried in to the laboratory for observation and study. 
There the blocks of plants were transferred to glass jars containing several 
inches of water. These jars were kept partially covered with glass plates. 
A dissection of the material this same evening (November 28) showed the 
following condition: The dehiscence of several antheridia was observed, the 
antherozoids being quite active, but most of the antheridia had not reached 
maturity. Many of the archegonia appeared to be mature, but it was 
difficult to find one in which the cap had burst and the pathway was open 
for fertilization. The ventral canal cell and the egg could be easily, seen in 
most of the archegonia. At this time of the year they stand out as two 
well defined balls of cytoplasm in the center of the archegonium. These 
rounded protoplasts are frequently so clearly defined in the living material 
that they can be accurately measured with an ocular micrometer. The 
same is also true of the nucleus of each protoplast. 
For the study of details a considerable amount of material was killed in 
a fluid made up as follows : 
Chromic acid crystals i g. 
Glacial acetic acid. i cc. 
Water 400 cc. 
The following method was employed. Using a pair of forceps with sharp, 
slender points, the colored buds were snipped quickly and easily out of 
each head, and were either transferred immediately to the killing fluid, or, 
if too many sterile branches were included, the latter were cut away in 
water under a dissecting microscope, using needles for the purpose, and the 
bud was then put into the killing fluid. The numerous very short side 
branches bearing archegonia form a firm, compact bud which may be handled 
by this method without the slightest injury to the archegonia, which latter 
are well protected by the perichaetial leaves closely investing them. 
During the period from December i to December 6 there were warm 
gentle rains. On the 6th a cold wave arrived, again freezing the bog. 
For the remainder of the month the weather was generally cold and dry 
with little snow. On December 26 a considerable amount of fresh material 
