PHYTOLOGY AND THERAPEUTICS. 97 
TABLE III. 
Weight in propor- 
Weight | Weight tion to number Rate per acre. 
No. of of | of dry of stalks. 
Puat, ES grain, | stalks, 
BOE SG er | SSI Grain, | Stalks, | Grain, | Stalks, 
pounds. | pounds. | bushels. | tons. 
Yellow soy: 
RR Re Coa cy siaiais) aja wie) 9:6\3:s/<,5"00 dose &5 2.875 4.562 3.246 5.152 23.27 1.10 
13) <n. Gaede DAE OEIOG ECO TORE edae 73 2.625 4.312 3.451 5.669 24.74 PAL 
(CS ABBE ADEE athe Ac eascise same 100 3.437 5.312 3.299 5.099 23.65 1.09 
Medium green | 
ee ttn santas com enincion War, 82 | 2.750 | ~8.3l2 3.218 9.730 23.07 2.09 
eee ees chetctaisias Gewurscarets srasda 67 2.125 6.125 3.044 8.775 21.82 1.88 
peer ces oh oie oe. oie. awe es an 32 | 3.062 7.812 3.584 9.144 25.69 1.96 
black. In all these cases, where the plants were inoculated with either soil or 
extract, numerous and well defined tubercles appeared on the roots. In a few 
instances, however, one or two tubercles were found on the plants not treated, 
but these were isolated cases and were undoubtedly due to infection resulting 
from the manipulation of tools and pots when the beans were planted. 
How Soon Do THE TuBERCLES APPEAR?—To obtain information on this 
point, a small bed was planted in the greenhouse June 19 and inoculated with 
Massachusetts soil, from which plants were taken up nearly every day to ascer- 
tain when the tubercles began to appear. They were first visible to the naked 
eye on July 3, thirteen days after the beans were planted, or eight days after they 
appeared above the ground. From this it would be inferred that the bacteria 
begin their work very soon after the young roots are formed and increase their 
activity with the growth of the roots. 
EFFECT OF STERILIZING THE Sori.— Pots of both Kansas and Massachusetts 
soil were sterilized by heating them to 200° C.(392°F.) The results obtained, 
both in the field and in pots, as well as by previous experience, showed that as 
far as the soy-bean organism was concerned the Kansas soil was already sterile. 
In the case of the Massachusetts soil, however, these results showed that the 
bacteria were killed at the above temperature, and plants grown in this soil pro- 
duced no tubercles except when inoculated. It might be well to state in this 
connection that the heating of the soil produced other effects than those of a 
bacteriological nature, and the plants grown in it did not possess a healthy and 
vigorous appearance. 
Prants Grown In MassacHusetts Sorit.—Since 21° of Massachusetts soil 
was capable of producing such good results, both in the field and in pots, it was 
thought that plants grown in this soil alone would give still more striking results 
in tubercle formation. One pot each of yellow soy and medium green were 
grown in Massachusetts soil. The plants did well and ranked among the best in 
the greenhouse, but on washing out the roots the tubercles were found to be only 
moderate in size but fairly well distributed over the roots. In fact they did not 
show up so well as plants which were inoculated with only a small portion of 
Massachusetts soil. This experiment is repeated and results given under the 
second series of experiments in the greenhouse. 
InocunaTina at Top, MippiLe, anp Borrom oF Potr.—To test the rapidity 
with which the organisms spread in the soil, three pots each of yellow soy and 
medium green were inoculated at the top, middle, and bottom of the pots respect- 
ively with 21°¢ of Massachusetts soil. The washing out of the roots revealed the 
fact that the plants inoculated at the top of the pot produced tubercles on the 
—T 
