UTILIZATION OF NITROGEN-FIXING POWERS OF LEGUMES Irs 
some cases it seemed to give favorable results, the success attend- 
ing its use was so uncertain that it fell into disrepute. Later, 
various improvements were introduced into the methods of 
making and distributing the cultures, and a new product, called 
New Nttragin, has been put forward which gives somewhat 
better results. This and other similar products, put up under 
various trade names, have been tested quite extensively and the 
results have been much more positive than in the earlier attempts. 
Meantime in the laboratories of the United States Department 
of Agriculture extensive experiments were carried out, seeming 
to show the possibility of increasing the nitrogen-fixing powers of 
these bacteria by cultivating them in solutions that are poor in 
nitrogen. After continued experiments in this line, cultures of 
the tubercle-producing organisms were sent out for testing from 
the department. These too proved unsatisfactory. They were 
first sent out upon absorbent cotton, but the bacteria did not 
live long on the cotton fibers and the farmers were likely to re- 
ceive cotton containing only dead bacteria. Then they were sent 
out in a liquid or upon agar with much more satisfactory results. 
During the last few years, indeed, there has been such demand 
for them that many of the Agricultural Experiment Stations in 
this country distribute them to farmers and several new brands of 
commercial cultures have been put on the market. One of the 
latest schemes, which seems to be quite successful, is to inoculate 
the bacteria into sterile soil and to distribute them in small tin 
boxes of soil. 
Methods for distributing the cultures are likely to be improved 
still more in the future. The plan is logically a proper one, and 
if it be found possible to develop the tubercle bacteria in sufficient 
quantity and to distribute them in a living condition, these soil 
inoculations may become of great value to the agricultural 
industry. 
The reasons for the frequent poor results are varied. The 
difficulties of keeping the cultures pure, of distributing them to 
