- 63 — 
After many trials and experiments I worked out the following 
schedule which gave uniformly good results. 
Schedule for imbedding Pellia epiphylla. 
Fixing solution 24 hours or more. 
Wash in running water 12 hours or more. 
15 per cent, alcohol, 3-6 hours. 
35 per cent. “ 3-6 hours. 
50 per cent. “ 3-6 hours. 
70 per cent. “ 6 hours-anytime. 
85 per cent. “ 4-12 hours. 
95 per cent. “ 12-24 hours, 
abs. alcohol 1st sol. 12 hours or more. 
“ “ 2nd “ 12 hrs. or more, 
abs. “ (^) "f xylol ( ) 24 hrs. or longer. 
“ “ (/4) + “ (/4 ) 24 hrs. or longer. 
“ “ (^) + “ (^) 24 hours or longer. 
Too much emphasis cannot be laid on the necessity of long periods 
in the last three solutions. 
xylol 1st sol. 12 hrs. or longer. Drain thoroughly, 
xylol 2nd sol. 2 or 3 hours or longer. 
Then begin to add paraffine very slowly in minute shavings. As the 
solution becomes saturated larger pieces may be added with greater 
frequency. The material seemed to be benefited by remaining some 
time in the xylol-paraffine mixture. A week or ten days gave good 
results, and apparently a longer time would do no harm. 
Soft paraffine melting at 37° C. was used and the greatest care 
was necessary to see that the temperature did not rise above that 
point. The shortest time that It was safe to leave the material in the 
paraffine oven was 24 hours, and during that time, the paraffine so- 
lution should be poured off at least three times and renewed v/ith 
shavings of paraffine of the same melting point. A longer time than 
twenty-four hours is desirable and the more times the paraffine is 
changed the better the result will be. 
In transferring from soft to hard paraffine, again the greatest care 
must be taken that the temperature of the latter shall not be too high, 
or shrinkage will result and all the painstaking work of previous days 
or weeks will be lost. One successful method is to heat the hard 
paraffine on an iron stand and allow it barely to reach the melting 
point, and then pour out into a paper tray. The material in the soft 
paraffine can then be taken from the oven and transferred to this and 
with hot needles each piece can be carefully oriented. The paper 
trays should then immediately be floated on cold water until thor- 
oughly cooled. If they are taken out of the water and allowed to 
dry thoroughly, the paper will easily peel off from the paraffine cakes 
