Seaweeds and Leaf-green 
to the fact of alge flourishing in such temperatures as 
these, but at any rate they do live at 52° C. and quite 
vigorously.® 
As seeds and spores, vegetable protoplasm is able to 
support far higher temperatures even than 70°C. Mosses 
have survived temperatures of 80° and go° C.!° Bacilli 
have been known to grow at 60° to 70° C“™ Seeds of 
certain flowering plants were not killed by exposure to 
enormous temperatures such as go° or 120° C.,” and a 
yeast spore revived after 130° C.8 
Perhaps the endurance of great cold is even more 
remarkable. 
‘Those very algz which thrive at 52° C. can with- 
stand a cold of —12° C, for four hours, and various 
spores of seaweed were not killed by —20° to —30° C.4 
Drs. Macfadyen and Rowland found that the spores of 
some bacteria began to grow again after they had been 
chilled for ten hours at a temperature of —252° C15 Not 
only so, but the seeds of several vegetables were kept 
for 130 hours at temperatures of —185° to —192° C, and 
were not much the worse, germinating quite satis- 
factorily after this awful and unimaginable cold ! #6 
It is very hard to understand such facts as these. 
How is it possible that living protoplasm can endure 
such horrible extremes of temperature which indeed 
can scarcely ever be produced naturally? No doubt 
the protoplasm must be dry and perhaps temporarily 
lifeless during the -process, but then how is it that its 
delicate complex mechanism is in full working order 
as soon as the conditions improve ? 
These facts are, however, quite sufficient to assure us 
that low forms of algze might have been in existence at a 
very early stage in the earth’s history and long before 
there were snow caps at the North and South Poles. 
It also explains why we find algz luxuriantly flourish- 
34 
