76 THE EVOLUTION OF LIFE 
or otherwise, of the statements which had been 
made to the effect that a previous desiccation enabled 
spores, in such a state, and when surrounded by their 
albuminoid or gelatinous envelopes, to resist for a 
long time the moistening influence of water, and 
thereby to withstand for long periods a degree of heat 
which would otherwise have proved destructive. 
To test this point I proceeded in the following 
manner. I took a hay infusion on which there was 
a well-formed scum containing myriads of the most 
typical spore-bearing filaments, partly entire and 
partly breaking up, so as to liberate the spores. 
This was put into a corked test-tube and shaken 
vigorously for a short time, so as to procure a 
uniform dissemination of the spores through the 
liquid. Some of the thick, muddy-looking emulsion 
was then poured upon an ordinary clean microscope 
slip, so as to cover it with a thin stratum of the fluid, 
which was subsequently allowed to evaporate. In 
the course of three or four hours, when a dry opaque 
layer had been left upon the glass, the slip was 
placed in the dry chamber of an incubator at a 
temperature of 122 F., where it was kept exactly 
four days. The dry layer was then scraped off 
with a knife into a clean watch-glass, and to the 
resulting powdery material about thirty or forty 
minims of distilled water were added. 
After allowing the powder to remain thus im- 
mersed for four hours, so as to imitate the stage of 
preparation of a hay infusion, some of the stirred-up 
mixture was added to a quantity of urine having an 
acidity equivalent to eleven minims of liquor potassz 

