10 LIFE OF A TREE. 
merated, and reflect upon them, he will certainly 
find in all that these three conditions exist :— 
yes even in the Arctic Regions there is at proper 
seasons enough heat, moisture, and air for a red- 
snow plant to live; although it is necessary to 
mention that its little cells do not properly belong 
to the class of seeds, and are not so dependent on 
these external circumstances. 
Up to this point we have spoken of the life 
of a seed as if it only commenced at the time 
when the first appearance of the little root and 
the young leaves occurs. But it is interest- 
ing to remember, that seeds are actually alive, 
strictly speaking, before they are committed to 
the earth; and some very curious particulars 
belong to this part of vegetable history. In 
proof of this, let the reader take a handful of 
wheat and put it into boiling water for a few 
minutes ; then let it be taken out and sown in 
the earth. They will never spring up; the seeds 
have been killed. 
Some interesting experiments on this subject 
were made by Messrs. Edwards and Colin. They 
found that at a degree of heat (125° Fahrenheit’s 
thermometer) which could be borne by the hand 
