BIBLIOGRAPHY. 137 



LAWES and GILBERT. — On the present question of the 

 sources of the nitrogen of vegetation. Phil. Trans. Roy. Soc. 

 CLXXX. B. 1-107. 1888. 



LIEBSCHER. — Assimilation of atmospheric nitrogen by 

 leguminous and non-leguminous plants. (Ein Beitrag zur 

 Stickstofrrage). Deut. landw. Presse 19: 1080, 1892. 



LIEBSCHER. — Concerning the nitrogen question. (Noch- 

 mals die Stickstoff frage). Deut. landw. Presse, 20: 1037, 1893. 



LOTSY, J. P. — A contribution to the investigations of the 

 assimilation of free atmospheric nitrogen by white and black 

 mustard. Off. Expt. Sta. Bui. 18, U. S. Dept. of Agr. Abstract, 

 Ex. Sta. Record V, 693. 



LOEW, O. — The synthetical powers of micro-organisms. 

 Science 23: 144. 1894. 



MAC DOUGAL, D. T. — Nitrogen assimilation by Isopyrum 

 biternatum. Geol. and Nat. Hist. Survey of Minnesota Bui. 9, 

 Part II, 1894. 



MASON, J. — Field experiments on the fixation of free nitro- 

 gen. Jour. Roy. Agr'l Soc. of England. 3 Ser. 3: 651. 1892. 



MOELLER, H. — Bemerkungen zu Frank's Mittheilung 

 fiber den Dimorphismus der Wurzellknollchen der Erbose. 

 Ber. d. deut. Bot. Ges. 10: 242, 1892. 



MOELLER, PI. — Reply to Frank regarding the dimorphism 

 of root tubercles of peas. (Entgegnung gegen Frank, betref- 

 fend den augeblichen Dimorphismus der Wurzelknollchen der 

 Erbse) Ber. deut. bot. Ges. 10, 568, 1892. 



MUNRO, J. M. H. — The nitrifying ferments of the soil. 

 Jour. Roy. Ag. Soc. England 3 Sen, 2: 702. 



NAUDIN, C. — The formation of root tubercles among leg- 

 umes. Jour. Agr. Prat. 58: 453, 1894. Abstract, Ex. Sta. 

 Record VI, 382. 



NAUDIN, C. — Root tubercles of legumes, their relation to 

 their host plants. Jour. Agr. Prat. 61 : 11,46. 1897. 



NOBBE, F. and HILTNER, L.— The interchange between 

 leguminous plants and the bacteria causing root tubercles 

 (Ueber die Wechselbeziehungen zwischen den Knollchenerzen- 

 genden Bakterien unci den Leguminosen,) Sachs, landw. 

 Zeitsch. 165, 1893. 



NOBBE, F. and HILTNER, L.— Are non-leguminous 

 plants able to assimilate free nitrogen? (Vermogen auch nicht- 



