especially poisonous ones. According to the investigations of 

 Rumm and Qjfchers, treatment with Bordeaux mixture causes a deep 

 green coloration of the plants under experiment. Pethjbridge 

 makes the same statement for his wheat plants, which were culti- 

 vated in a solution containing sodium chlorid""". 



Just as in the formation of chlorophyll, a metaplastic 

 change of the cell character can also he produced in tissues nor- 

 mally colorless, by the development of red pigraemt dissolved in 

 the cell sap. As mentioned above (p, 38}, the formation of this 

 red pigment ±s dependent in many plants on the action of light 

 and of good nutrition, and may therefore be suppressed by the re- 

 moval of light and of nutritive materials. Conversely, the ques- 

 tion must now be asked, v/hether the production of i-ed oolorirg 

 matter can be induced in cells, normally colorless, by the effect 

 of light on organs which, under normal conditions, are developed 

 in the dark, or likewise by a surplus of light, or, further, by 

 an increased supply of nutritive material. In fact the observa- 

 tions on Gal luna vulgari s . Azolla and many others show that es- 

 pecially Intense lighting causes a red coloration „ -The same is 

 true of many succulents Topuntia, Sedum and others)^. It has 

 been proved further that plants transferred from the plains to 

 high mountains, often develop red coloring matter in the new hab- 

 itat, -supposedly under the influence of the Alpine abundance of 

 light . The same red coloration as an effect of intense lighting 

 is conspicuous in the vegetation of the far North^, Finally or- 

 gans which under normal conditions are kept from the action of 

 the light, such as roots and others, are often colored red, if 

 they are forced to live in the light (roots of Salix", Zea, 

 Begonia and others). 



Further the question must still be asked as to the influ- 

 ence of the food supply on metaplastic pigment -format ion. Overtoil^ 

 has shown that in plants of the most varied kinds, the formation 

 of red coloring matter - often indeed extraordinariljr prolific - 

 takes place if opportunity is given the plants to take up an 

 abundance of sugqr (grape, invert- or cane-), leaves of Taraxaxum, 



^ Compare „f or example Rumm: Ueb. d. Wirkung der Kupferpra- 

 parate bei Bekampfung der sog. Blattfallkrankheit der Weinrebe. 

 Ber. d. D. Bot, Ges. 1893, Bd. XI, p. 79. Pethybridge, Beitr. z. 

 Kenntn. d. Einwirkung d. anorg. Salze auf die En twi eke lung and 

 d. Bau. d. Pfl. Dissertation Gottigen 1899.- Some observations 

 on the inf luence of the nucleus on the growth and formation of the 

 ch:j,orophyll bands in Spirogyra by Gerassimoff, Abhangigkeit d. 

 Grosse d, Zelle v. d. Menge ihrer Kemmasse. Zeitschr. allg. 

 Physiol, 1902, Bd. 1, p, 220, 



^ Compare Mchl. Vermischte„Schriften, 1845, p. 386, 390; 

 further Askenasy, Ueb. d. Zerstoriaag d. Chlorophylls lebender Pfl. 

 durch d. Licht. Bot. Zeitg. , 1875, Bd. XXXIII, p. 497. Pick, Ueb. 

 d, Bedeutung d, rgten Parbstoffes bei d» Phanerogamen u. die Be- 

 zieh. ders. z. Starkewanderung. Bot. Cbl., 1883, Bd, XVI, p. 315. 

 DeVries, Ueb. d. Aggregation im Protoplasma v. Drosera rotundi- 

 folia. Bot. 2eitg. , 1886, Bd. XLIV, p. 1 and many others. 



3 Compare Kerner, Pflanzenleben, 1898, Bd. II. 



* Wulff, Th. Bot. Beobacht. aus Spitzber;g|n. Lund I90H. 



5 Compare also Schell, Ueb. Pigmentbil^ung in d. Wurzeln 

 einiger Salix-arten 95. Naturf .-Vers. Kasan. Russisch. (Just s 

 Jahresber., Bd. V. p. 562). 



6 Beob, u. Versuche ub, d. Auftreten v. rotem Zellsaft 

 T--4 -nj!-! TS^TT,^^!^^!^'?* Jahrb. f. wiss. Bot., 1899, Bd. XXXIII, 



