84 INFLUENCE OF THE EXTERNAL CONDITIONS ON GROWTH 



Archiv. Neerlandaises, 1870, T. v); Haberlandt, Versuchsst, 1874, Bd. xvn, p. 113, 

 and Wiss. pract. Unters. a. d. Gebiete des Pflanzenbaues, 1875, I, p. 109 ; Tietz, 

 Keimung einiger Coniferen u. Laubholzer, 1874; Just, Cohn's Beitr. z. Biolog., 

 1877, Bd. u, p. 324; N. J. C. Miiller, Bot. Unters., 1879, Bd. n, p. i ; Kirchner, 

 Cohn's Beitr. z. Biolog., 1883, III, p. 339; Askenasy, Ber. d. Bot. Ges., 1890, 

 p. 61. Tabulated summaries are given by Nobbe, Samenkunde, 1876, p. 231; 

 Detmer, Vergl. Physiol. d. Keimungsprocesses, 1880, p. 425. 



ALGAE. Oltmanns, Jahrb. f. wiss. Bot., 1891, Bd. xxm, p. 358; Klebs, 

 Bedingungen d. Fortpflanzung, 1896, and the literature there quoted. 



FUNGI. Literature is given by de Bary, Pilze, 1884, pp. 375, 379; Zopf, 

 Pilze, 1890, p. 201. Also Cohn, Ber. d. schles. Ges. f. vaterl. Cultur, 1888, 

 p. 150; Schostakowitsch, Flora, Erg.-bd., 1895, p. 369; Thiele, Temperaturgrenzen 

 d. Schimmelpilzes, 1896; Klebs, Bedingungen d. Fortpflanzung, 1896, p. 446 seq. ; 

 Jahrb. f. wiss. Bot, 1899, Bd. xxxin, p. 549; 1900, Bd. xxxv, p. 80. 



SACCHAROMYCES. Pedersen, Rech. s. 1. propagation d. 1. levure, 1878; Hansen, 

 Meddelelser f. Carlsberg Lab., 1888, T. n, French abstract, p. 114. Summaries 

 by Jorgensen, Mikroorganismen d. Gahrungsindustrie, 1898; Ad. Mayer, Gahrungs- 

 chemie, 1895, 4. Aufl., p. 150. 



BACTERIA. Literature is given by Fliigge, Mikroorganismen, 1896, 3. Aufl., I, 

 p. 132; Migula, System d. Bact, 1897, I, p. 358; Lafar, Techn. Mykologie, 1897, 

 I, p. 70. On thermophile bacteria : Rabinowitsch, Zeitsch. f. Hygiene u. 

 Infectionskr., 1895, Bd. xx, p. 154; Kedzior, Centralbl. f. Bact., 1897, 2. Abth., 

 Bd. in, p. 154; Miyoshi, Journal of the College of Science, Tokyo, 1897, Vol. x, 

 p. 143; Laxa, Centralbl. f. Bact., 1898, 2. Abth., Bd. iv, p. 362; Tsilinsky, 

 Ann. d. PInstitut Pasteur, 1899, T. xin, pp. 500, 788; Sanies, Centralbl. f. Bact., 

 i. Abth., 1900, Bd. xxvni, p. 444; Michaelis, Centralbl. f. Bact., 2. Abth., 1900^ 

 Bd. vi, p. 231. 



PART III 

 THE INFLUENCE OF LIGHT 



SECTION 23. General. 



MAMY bacteria and fungi are able to live and grow in complete 

 darkness, but exposure to light forms one of the essential conditions for 

 the complete development of all green plants which obtain their organic 

 food by photosynthesis. Hence such plants grow slowly or not at all in 

 the shade of dense woods, or beneath a certain depth of water. In addition 

 to its importance as a source of energy, the shape and growth of particular 

 organs, or of the entire plant, are influenced by light, as is instanced by the 

 abnormal shapes of seedlings grown in darkness, as well as by the non- 

 formation of chlorophyll. This influence of light is not confined to green 



