SOIL INOCULATION, 211 



The highest plants and the heaviest crop were attained from 

 the seeds treated with lupine nitragin. Pea nitragin had no 

 appreciable effect. The pots given tubercles of swainsona and 

 of horse bean, were both inferior to those receiving no germs; 

 but in the pots receiving no germs, tubercles were found, so 

 that there must have been some source of infection, — possibly 

 the drip from the roof. 



In general, the differences with the different cultures were 

 so slight as to be unappreciable, and were not greater than those 

 found in the different pots receiving no germs. 



VETCH. 



Treated in every way as were peas and clover. When just 

 beginning to bloom, the plants were harvested. The results 

 were, in every way, comparable to those from the pea, detailed 

 above. In no case were there sufficient differences to indicate 

 even a possible advantage from the use of "the germ culture. 



BEAN. 



The remarks concerning the vetch will apply with equal force 

 to the bean. With the bean, however, there was no evidence 

 of tubercles in any of the pots. It should be said that the beans 

 were kept in the same house with the other plants, and it is 

 possible the unfavorable temperature may have affected the 

 results. 



A duplicate lot, started a month later, was allowed to come to 

 maturity before harvesting. The plants were yellow and 

 showed lack of vigor, because of low temperature. There was, 

 however, no appreciable difference in the size or appearance of 

 the various lots. It is worthy of note that the plants in one 

 pot inoculated with horse bean tubercles produced small spher- 

 ical tubercles, about the size of a sweet pea seed. Every plant, 

 in soil inoculated with swainsona, produced tubercles, and those 

 in two of the pots given lupine nitragin. Plants from soil 

 inoculated with clover nitragin, pea nitragin, and from the 

 uninoculated soil produced no tubercles. 



J4 



