RESPIRATION 9 
I. RESPIRATION 
Every one of us, irrespective of age, knows quite 
well that in order to remain alive, even for a very 
few minutes, we must keep on breathing, and that is 
true of the plants as well. If we deprive them 
altogether of oxygen they die inevitably: they 
must breathe ceaselessly in order to remain alive. 
Respiration is indeed a very difficult subject, neverthe- 
less it is common knowledge that we take air into our 
bodies through two holes, which we call our nostrils. 
We must not go into the question of what happens 
to it or what it does when it gets into our lungs, but 
we must be content with the simple and well-known 
fact that air enters our body for breathing purposes 
through holes ; our own are large enough to be seen 
quite easily, and, except for the fact that some people 
make the mistake of breathing through their mouth 
as well, they are confined to our two nostrils. But 
what about the plant? It will perhaps be some- 
what of a surprise to learn that it, too, admits air into 
its body through holes. They are too small to be 
seen without the aid of a microscope ; we can, however, 
locate them quite easily with the help of a lens, which 
every lover of Nature, whether student or not, should 
possess, carry about with him, and use frequently. 
We shall also require a little cold water, a glass 
rod, a glass “slip,” and a “‘ cover.” The last three can 
be obtained from any optician at a trifling cost. 
We shall want the rod for transferring some water 
drop by drop on to the slip. Slips are pieces of thin 
glass used as slides for the microscope, a very conve- 
nient size being three inches by one. The cover is 
the small piece of very much thinner glass that is 
