98 KANSAS ACADEMY OF SCIENCE. 
upper portion of the roots with only a few extending downward and none on the 
lower portion of the roots. The plants inoculated at the middle of the pot pro- 
duced tubercles about midway between the upper and lower portion of the roots. 
And, lastly, the plants inoculated at the bottom of the pot showed the tubercles 
on the lower portion of the roots, with a few tending upward. Thisis a very in- 
teresting point, and indicates that, without mechanical mixing, the micro-organ- 
isms spread very slowly in the soil, and that in spite of the fact that the plants 
were frequently watered on upper surface of pot, which one might suppose 
would have carried the bacteria deeper into the pots. The number and position 
of the tubercles are shown in the accompanying drawings. 
Fig. 1. Fig. 2. 
Soy-bean inoculated at top of pot. Soy-bean inoculated at middle of pot. 
FURTHER EXPERIMENTS IN THE GREENHOUSE. 
Puiants Grown IN Pure Massacuuserrs Soit.—Fearing that the results 
obtained in the previous experiment might be due to local conditions or disturb- 
ances, the subject was further tested by planting yellow soy-beans in seven pots 
of pure Massachusetts soil, and comparing with these seven pots of Kansas soil, 
all of which were inoculated with 21° of Massachusetts soil. The results ob- 
tained were similar to those of the previous experiment, only that no appreciable 
difference could be seen in the results of the two treatments. Why a soil so thor- 
oughly infected with micro-organisms as was this Massachusetts soil should not 
cause greater development of tubercles isa question not readily answered, and 
one that will bear further investigation. 
INOCULATING WITH DIFFERENT AMOUNTS OF MassacHusetts Sort.—To test 
the effect of varying amounts of Massachusetts soil on the number and size of 
tubercles produced, ten pots of yellow soy-beans were grown in which the soil 
had been inoculated with 21° of Massachusetts soil for pot 1, 42° for pot 2, and 
so on, increasing 21° for each succeeding pot, until the tenth pot was reached, 
which received 210° of Massachusetts soil. No particular difference could be 
detected in the growth of the plants, and what was true of the upward growth 
was likewise found to be true of the roots and tubercles. The differences were 
slight, and these so irregular that it could not be said that one was any better 
