BACTERIA ON THE SURFACE OF PLANTS. 



35 



was alkaline. In case of fungus growths the reaction was acid. The constant occurrence of 

 the bacteria or of the fungi in the interior of the water calyx in no way injures the host 

 plant. The author ascribes the presence of bacteria or 

 fungi to alkaline or acid secretions of the plant, but 

 inasmuch as he seems to have determined the reaction 

 only after the organisms had grown in the fluid, his con- 

 clusion does not necessarily follow. 



These organisms are really still outside of the plant. 

 Their presence here, while extremely interesting, is only 

 to be compared with what occurs in the mouth-secretions 

 of animals, and it is doubtful if there is any true sym- 

 biosis, i. e., mutual profit. 



The most recent reference to this subject, so far as 

 known to the writer, occurs in an address by M. C. 

 Potter (Trans. British Myc. Soc., 1910, Vol. Ill, p. no) 

 from which fig. 5 is borrowed. He found numerous 

 bacteria on the surface of leaves (potato, artichoke, etc.), 

 and cultivated them therefrom by making impressions of the leaves on gelatin plates. 



LITERATURE. 



Fig. 5* 



1890. 



1893. 



1896. 



1897. 



1901. 



1902. 



TREUB, M. Les bourgeons floraux du Spatho- 

 dea campanulata Beauv. Annales du Jardin 

 Botaniquc de Buitcnzorg, vol. viu, 1890, pp. 

 38 to 46, 3 plates. 



WiESNER, JULIUS. Ueber ombrophile und 

 ombrophobe Pflanzenorgane. Sitzungsb. K. 

 Ak. d. Wissenschaften, Math. Naturw. Classe. 

 Wien., 1893, Bd. 102. Abt. I, pp. 503-521. 

 See also Wiesner: Pflanzenphysiologische 

 Mittheilung aus Buitenzorg (m). Ueber den 

 vorherrschend ombrophilen charakter des 

 Laubes der Tropengewachse. Ibid., 1894, 

 Bd., 103, pp. 169-191. 



HOFFMANN, F. Untersuchungen uber die 

 Grosse der Mikroorganismenzahl auf Getreide- 

 kornern unter verschiedene Bedingungen. 

 Wochenschrift fur Brauerei, Jg. xm, 1896, 

 No. 44. [Not seen.] 



KOORDERS, S. H. Ueber die Bliithenknospen 

 Hydathoden einiger Tropischen Pflanzen, pp. 

 354 to 477, 8. Das constante Vorkommen 

 von Bacterien oder von Fadenpilzen im Inneren 

 der Wasserkelche. Annales du Jardin Bo- 

 tanique de Buitenzorg, 1897, vol. xiv, pp. 

 451 to 452. 



WURTZ, R. ET BOURGES, H. Sur la presence 

 de microbes pathogenes a la surface des 

 feuilles et des tiges des vegetaux qui se sont 

 developpes dans un sol arrose avec de 1'eau 

 contenant les micro-organismes. Arch, de 

 Med. Experim. et d'Anat. Pathol., Paris, 

 1901, Ser. i to 13, pp. 575 to 579. 



PAPASOTIRIU, J. Untersuchungen uber das 

 Vorkommen des Bakterium coli in Teig, Mehl 

 und Getreide, nebst einigen Bemerkungen 

 uber die Bedeutung des Bakterium coli als 

 Indikator fiir Verunreinigung von Wasser mit 

 Fakalien. Archivfur Hygiene, 41 Bd., Miin- 

 chen and Berlin, 1902. Verlag von R. Olden- 

 bourg, pp. 204-210. 



1902. 



1903. 



1904. 



1905 



1905. 



1906. 



1907. 



1910. 



CHRZASZCZ, T. Die Mikroorganismen der 

 Gersten und Malzkorner. Wochenschrift f. 

 Brauerei, Jg. xix, 1902, No. 40. [Not seen.] 



BURRI, R. Die Bakterien vegetation auf der 

 Oberflache normal entwickelter Pflanzen. 

 Centralb. f. Bakt, 2 Abt., x Bd., pp. 756 

 to 763. 



DUGGELI, MAX. Die Bakterien flora gesunder 

 Samen und daraus gezogener Keimpflanzchen. 

 Centralblat f. Bakt., Jena, 1904. n Abt., 

 Band xn, pp. 602 to 614, and 695 to 712, 

 1904, Band xm, pp. 56 to 63 and 198 to 207. 



METCALP, H. Organisms on the surface of 

 grain, with special reference to Bacillus coli. 

 Science, N. S., vol. xxn, No. 562, 1905, pp. 

 439-441. Also a separate. 



SMITH, ERASTUS G. Note on the occurrence 

 on grain of organisms resembling the Bacillus 

 coli communis. Science, N. S., vol. xxi, 1905, 

 pp. 710 to 711. 



PRESCOTT, SAMUEL C., with cooperation of 

 ERASTUS G. SMITH, WILLIAM J. MIXTER AND 

 SELSKAR M. GUNN. The occurrence of organ- 

 isms of sanitary significance on grains. Biolo- 

 gical Studies by the Pupils of William Thomp- 

 son Sedgwick, Boston, June,i9o6, pp. 208-222. 



BARBER, MARSHALL A. On heredity in certain 

 micro-organisms. Kansas University Science 

 Bull., March, 1907, vol. iv, No. i (whole 

 series, vol. xiv, No. i), pp. 3 to 48, plates 

 I to iv, and 3 text fig s. 



POTTER, M. C. Bacteria in their relation to 

 plant pathology. The British Mycological 

 Society, Transactions for the Season 1909, 

 vol. in, part 3, published May 2, 1910. I 

 plate, pp. 150-168. See also Centralb. f. 

 Bakt., 2 Abt., xxvtn Bd., pp. 624-640. 



*FiG. 5. Impression of leaf of Helianthus tuberosus on gelatin after 3 days' incubation. The form of the leaf is 

 outlined by the development of numerous bacterial colonies, germs of which were present on the surface o 



