manner those methods already known of propagating the
nitrogen-collecting bacteria which thrive on alfalfa, clover, peas, soya
beans, and other leguminous plants. Almost every country is now devoting
time, money, and energy to agricultural research work. In 1908 the
Agricultural College at Ontario prepared no less than 474 packages of
Legume Bacteria, and in 309 cases beneficial results followed from the
application thereof to the soil; in 165 cases no improvements in the
crops were noticed, this may, however, have been due to the want of
knowledge of how to manipulate the bacteria, or to lack of experience in
noting effects scientifically, but in any case the experiment must be
considered successful when the results obtained were satisfactory in no
less than 65 per cent. of the trials. No greater factor exists than the
microscope in opening up and hunting out the secrets concealed in the
very soil we are standing on.

If soils were composed of nothing but pure silica sand, nothing would
ever grow; but in Nature we find that soils contain all sorts of mineral
matter, and chief amongst these is lime.

Alfalfa thrives on land which contains lime, and gives but poor results
where this ingredient is deficient. The explanation is simple. There is
a community of interest between the very low microscopic animal life,
known as bacteria, and plant life generally. In every ounce of soil
there are millions of these living germs which have their allotted work
to do, and they thrive best in soils containing lime.

If one digs up with great care a root of alfalfa (it need not be an old
plant, the youngest plant will show the same peculiarity), and care is
taken in exposing the root (perhaps the best method is the washing away
of the surrounding earth by water), some small nodules attached to the