TJie Smirees of the Nitrogen of our Legumino^is Croj^s. G87 
Bobinia nodule, or Bohinia soil bacteria. On the other hand, 
the Bohinia nodule bacteria, which showed no action with peas, 
had marked effects on Bohinia. Still, this did not apply in all 
cases, there being sometimes more produce, and more nitrogen 
gained, under the influence of the microbe infection from 
another than from the same description of plant. In some 
cases infection had more effect than manuring with ammonium- 
salts or nitrate. Nobbe concludes, however, that the results can 
leave no doubt that the pea and the Bohinia bacteria have dif- 
ferent physiological actions, which indicate, if not different 
species or varieties, at any rate different race or nutiition modi- 
fications. 
Beverinck also concludes that the various papilionaceous 
bacteria differ more than he had formerly supposed. Thus, he 
found that Vicia Faha, infected with the bacteria from Ornithoims, 
produced no nodules ; and he considers that the difference 
between the bacteria of beans and serradella accounts for the 
fact that serradella had no nodiiles when growing in a garden be- 
tween beans which had numerous nodules. 
Of the three descriptions of leguminous trees upon which 
Xobbe experimented, the Bohinia and the Cijtisus, which are 
both of the papilionaceous sub-division of the leguminous family, 
were susceptible to microbe infection, and nodule-formation on 
their roots, and showed coincidently gain of nitrogen ; but the 
GleiUtschia, which is not papilionaceous, but of the sub-order 
C'i-salpiniefp, was quite indifferent to such infection, although 
both soil-extracts and pure cultivations from various sources 
I were tried. On the other hand, it was found that the application 
of calcium nitrate and ammonium sulphate gave considerably 
increased growth. Xobbe observes that the roots of Gleditschia 
have a very thick covering which it would be at any rate 
difficult for the bacteria to penetrate ; but whether the members 
of this group generally behave differently from the Pcqnlionacecp 
in this respect remains for future investigation to determine. 
It is at any rate of interest to note that the only leguminous 
plant outside the papilionaceous sub-order which has yet been 
experimented upon has not been found susceptible to infection, 
or to have nodules on its roots. 
Difference ix the E.xterxal Character of Legumixous 
root-xodules. 
The conclusion drawn from the evidence which has been 
cited — that there are various nodule-forming bactei'ia — is at 
any rate consistent with the descriptions which have been given 
