66 BOTANICAL GAZETTE [jaxuary 



lus (3), Hedysarum, Lathyrus, Capnoides (2), Lepidium (3), Thelypodium (2), 

 Pleurophragma, Sophia (2), and Arabis.— J. M. C. 



Ammonifying soil nitrogen.— Lipman has made another valuable contribution 

 to soil bacterioIog)'.='° His experiments were exceedingly well planned, were 

 fundamental, and in most cases gave consistent results. So much detail is included 

 in the report that a satisfactory summary of the article is impossible. 



amm 



peptone, and solutions containing peptone and inorganic salts. The addition of 

 the salts favors the growth of certain species of bacteria and also ammonification 

 under certain conditions. These species wxre unequally distributed in soils. 

 Inoculation with soil infusion was decidedly inferior to inoculation with soil itself. 

 But soil infusions in the same sterile soil exhibit relations similar to those of the 

 corresponding direct soil inoculations. The inoculation of sterile soils in various 

 ways shows that in ammonification the bacterioIoOTral soil fartnr i?i much more 



ammon 



important than the chemical one. Manured soils showed a superio __ 

 power. Peptone salt solutions which are not provided with too large a quantity 

 of mineral are most suitable for study of the general condition of the bacterial 

 flora of the soil. The differences in the power of ammonification exhibited by 

 several soils seem to bear no direct relation to their mechanical composition. The 

 amount of the sterile soil which is inoculated affects the peld of ammonia, the 

 amount of ammonia being larger, in nearly ever>' case, in the larger samples of 

 soil. This may be due to increased production of ammonia bv ammonification 



substances 



amount 



absorption of deleterious products by the soib. Old samples of soil kept in a 



sam 



laboratoiy for several months. 



ammonifymg power than tne 

 onifying power of the different 

 fter keening the samples in the 



ula 



ulus increasing with the amount of lime up to two tons per acre. The author 

 sugg^ts that it may be possible to develop a bacteriological method of determining 

 tite lime reqnh^ments of soils in general. More consistent results were obtained 

 by soluble nitrogenous material, such as peptone and gelatin, than by insoluble 

 substances, like albumen, casein, and cotton-seed meal. As a rule, ammonia is 



amounts 



^ ,^*xij-i«u ud^.^, aau m some cases they were larger. 



Working with Azotobacter, LmL^v found that small quandties of soil did not 

 furnish enough mineral salts, whereas in larger quantities a normal growth was 

 obtained. He therefore suggests that it mzy be possible to measure the mineral 



soil nitrogen. ReptHt N. J. Agri( 



ammosxifiGatioa 



»TI;4 



