78 THE ROYAL SOCIETY OF CANADA 
for conveniently short periods of time. If it should be found that the 
vitality of such plant structures when they are kept dry, in vacuo, in 
the dark, persists indefinitely, i.e., for many years longer than usual, 
then the hypothesis of entire suspension of vitality will receive strong 
support. If, on the other hand, experience should show that any seeds 
or spores or fruit-bodies, when kept under these conditions, nevertheless 
lose their vitality, positive evidence will be forthcoming that after all 
the vitality has not really been temporarily suspended. Our experi- 
ments with the unopened tubes of Schizophyllum commune still at our 
disposal, are planned to extend, if necessary, over a period of 25 years. 
Summary of the Chief Results. 
Fruit-bodies of Daedalea unicolor can retain their vitality when 
dried, kept in the dark, and exposed to ordinary air at room tempera- 
tures, for at least seven and a half years, and those of Schizophyllum 
commune for at least five years and seven months. 
Fruit-bodies of Schizophyllum commune, after previous thorough 
drying by exposure to phosphorus pentoxide in vacuo, retain their 
vitality after being kept for sixteen and a half months in a vacuum at 
a pressure of not more than one-tenth of a millimetre of mercury, in the 
dark at room temperatures. 
In their retention of vitality, when dried, exposed to ordinary air, 
or kept in vacuo, the fruit-bodies of certain Hymenomycetes resemble 
the seeds of Higher Plants, and the spores of Moulds. 
Departments of Botany and Physiology, 
University of Manitoba, 
Winnipeg. 
ADDENDUM. 
Since the above was written some further experiments have been 
carried out at the University of Birmingham. It was found that 
fruit-bodies of Schizophyllum commune retain their vitality when dried, 
kept in vacuo, and at the temperature of liquid air for three weeks. 
A further account of these experiments will be given in another place. 
A.H.R.B. 
