. 
154 BACTERIA IN RELATION TO PLANT DISEASES. 
By careful washing, the spheres of Volvox were freed from pond water and placed by means of a 
sterile platinum loop in a sterile nutrient solution consisting of 200 cc. of water containing 4.0 mannit, 
0.1 of potassium phosphate, 0.05 of magnesium phosphate, and 0.3 of calcium carbonate. At the 
end of 10 weeks this solution contained 11.6 mg. of combined nitrogen. The only possible source 
of this nitrogen was the assimilation of the atmospheric nitrogen, absorbed in the water. Azotobacter 
had developed abundantly. 
The infection with Azotobacter was possible only through the introduction of Volvox to the 
surface of which some of these organisms were clinging. 
Reinke’s conclusion is that Azotobacter, while drawing its carbon in organic form from the 
Volvox, farnished the latter with nitrogen compounds. He is convinced that this theory concerning 
the source of nitrogenous compounds for both fresh and salt water alge is worthy of preference over 
every other hypothesis. As a further support for his theory he mentions the fact, discovered by 
Gerlach and Vogel, that the dry substance of Azotobacter contains 10 to 12 per cent of nitrogen. 
In 1904, Hugo Fischer published a short article on an assumed symbiosis between 
Azotobacter and Oscillaria living on the ground. 
He obtained samples of dark green Oscillaria from different localities, and covered them 
with a 1 per cent solution of mannit, according to Beyerinck’s method. There was such a 
rapid development of Azotobacter in pure culture that he was forced to assume an especially 
favorable growth of it among the filaments, although he could not demonstrate it micro- 
scopically. From this common occurrence together, he concludes that a symbiotic relation 
exists by which the bacteria furnish nitrogen compounds to the alge taking in return from 
their supply of carbohydrates. The earlier assumption, therefore, that the lower alge are 
able to assimilate free nitrogen should, he thinks, be retracted. 
LITERATURE. 
INSECTIVOROUS PLANTS. 
1875. MorreN, E. Observations sur les procédés in- | Arbeiten d.St. Petersburger Naturf. Gesellsch., 
secticides des Pinguicula. Bull. de l’Acad. | 1891, Abt. f. Bot., pp. 33-37, and Rothert in 
Royale des sciences des lettres et des beaux- Bot. Centralbl., Bd. Lr, p. 322, Bd. L, p. 304. 
arts de Belgique. Bruxelles, 1875, 2 sér. T. 1897. VuiNES,S.H. Proteolytic Enzyme of Nepenthes. 
XXXIX, pp. 870-881. Annals of Botany, 1897, vol. x1, pp. 563-584. 
' : A 898. VinEs, S. H. The proteolytic enzyme of 
1889. TiscuuTKin,N. Die Rolle der Bacterien bei der : y y 
Verdnderung der Eiweisstoffe auf den Blattern Nepenthes (11). Annals of Botany, 1898, vol. 
sare . XII, PP. 5457555- 
von Pinguicula. Berichte der d. bot. Ges.,1889, 1899. CLAUTRIAU, GEORGES. La Digestion dans les 
| 
| 
| 
| 
Bd. vu, pp. 346-355- pape | Urnes de Nepenthes. Mém. couronnés. Acad. 
1890. Dusors, R. Sur le prétendu pouvoir digestifdu | roy. de Belgique, 1900, Tome LIx, pp. 1-54 
liquide de l’urne des Nepenthes. Comptes | Bibliography of 31 titles. , : i 
Rendus des sé. de l’Acad., des Sci., 1890, T. cxt, 1901. VinES, S. H. The proteolytic enzyme of 
Pp. 315-317. . Nepenthes (111). Annals of Bot., 1901, vol. 
1892. ‘TISCHUTKIN, N. Uber die Rolle der Mikroor- XV, Pp. 563-573. 
organismen bei der Ernahrung insektenfres- 1910. WHITE, JEAN. The proteolytic enzyme of 
sender Pflanzen. Acta Horti Petropolitani, Drosera. Proc. Roy. Soc., Bd. 83, Ser. B. 
Vol. x11, No. 1, 1892, pp. 1 to 19. See also 562, 1910, Pp. 134-139. 
Hops. 
1892. Mout, ANT. Ueber die Bildung des Lupulins | tralbl., Heft v, 1892, Jahrg. I, pp. 13-18, 1 page 
und den Micrococcus humuli Launensis. | of figures. See also Allg. Brauer-u. Hopfenzeit. 
Osterreichisches Landwirtschaftliches Cen- | 1892, Bd. 47, p. 753. 
ALGAE. 
1894. Kossowirscu, P. Untersuchungen iiber die Berichte der deutschen botan. Gesellschaft, 
Frage, ob die Algen freien Stickstoff fixiren. Berlin, 1903, Bd. xx1, pp. 371-380. 
i geno Zeitung, Jahr. 52, Leipzig, 1894, 1903. eee Jomaleae. epee far ihn und 
. 97-116. zotobacter. er. d. d. bot. .» Berlin, 
1896. BourtHac, Raouu. Sur la fixation de l’azote | 1903. Bd. xx, pp. 481-483. . 
atmosphérique par l'association des algues et | 1993: fee ass W., und Keutner, J. Uber stick- 
des bactéries. Compt. Rend. dessé.del’Acad. | oe — Bakterien aus der Ostsee. 
des Sci., Paris, 1896, T. 123, pp. 828-830. Ae ad pacpabatr noe Gesellsch., 1903, 
1900. KricEerR, W. und ScHNEIDEWIND, W. Sind 1904. FISCHER taoon: Geer Seaiioes von Azoto- 
niedere, chlorophyllgriine Algen imstande, den bacter mit Ostillarien. Centralbl. £. Bakt 
freien Stickstoff der Atmospharezuassimilieren | 1904, 2 Abt., Bd. x11, pp. 267-268. A 
und den ae = Stickstoff zu bereichern? | 904. BoumHAC, ET GIUSTINIANI. Sur des cultures de 
acer Ja " - er, Berlin, 1900, Bd. 29, pp. | diverses plantes supérieures en présence d’un 
771-804. 3 oh ; mélange d’algues et de bactéries. Compt. 
1903. REINKE, J. Die zur Ernahrung der Meeres- | Rend. des sé. de 1’Acad. des Sci., Paris, 1904, 
rganismen disponiblen Quellen an Stickstoff. | Tome 138, pp. 293-296. 
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