besides Mr. Johnston says it is better to use the infected sweet
clover soil and there is no need of paying $2 an acre for something
we knew nothing about, and especially on land that is not worth more
than $2 an acre."

"I don't care what it's worth," she replied, "some of it cost your
grandfather $68 an acre, and it will never be sold for any $2, while
I have any say so about it."

They waited for Percy to proceed.

"The individual bacteria are very short-lived," he continued, "and
products of decay soon begin to accumulate in the tubercles. These
products contain, in combined form, nitrogen which the bacteria have
taken from the air, and in this form it is taken from the tubercles
and absorbed through the roots into the host plant and thus serves
as a source of nitrogen for all of the agricultural legumes.

"It should be kept in mind, of course, that the red clover has one
kind of nitrogen-fixing bacteria, that the cowpea has a different
kind, and that the soy bean bacteria are still different, while a
fourth kind lives on the roots of alfalfa and sweet clover."

"How much infected sweet clover soil would I need to inoculate an
acre of land for alfalfa?" asked Mr. West.

"If the soil is thoroughly infected, a hundred pounds to the acre
will do very well if applied at the same time the alfalfa seed is
sown and immediately harrowed in with the seed. If allowed to lie
for several hours or days exposed to the sunshine after being spread