2 24 PHYSIOLOGY OF NUTRITION 



but remain alive for a time, and the evolution of carbon dioxide continues. 1 

 Ethyl alcohol is usually formed also. 2 This anaerobic, or intramolecular, res- 

 piration is mainly the same as alcoholic fermentation. 



Sometimes the amount of carbon dioxide produced with access of oxygen 

 is the same as in the absence of oxygen, but such cases are rare; usually carbon 

 dioxide production is considerably less when oxygen is not available. 3 The 

 value of the ratio of the amount of carbon dioxide liminated anaerobically to 

 the amount given off in the same time in the presence of oxygen is given below 

 for several plants. 



Young seedlings of Vicia faba (Windsor bean) i . 197 



Young seedlings of Triticum vulgare (wheat) o . 490 



Y'oung twigs of Abies excelsa (fir) o . 077 



Young twigs of Ligustrum vulgare (privet) o . 816 



The amount of carbon dioxide formed in anaerobic respiration is primarily 

 dependent upon the carbohydrate content of the plant in question. 4 Etiolated 

 bean leaves produce but very little carbon dioxide in the absence of oxygen, and 

 die within two days. If they are previously kept with their petioles in sugar 

 solution for some time, being then placed under anaerobic conditions, they pro- 

 duce much carbon dioxide and live much longer than when they are employed 

 without the preliminary sugar treatment. After two days they are still alive 

 and they afterwards become green if illuminated. 



In anaerobic respiration, alcohol is formed only from carbohydrates. Sev- 

 enty-one etiolated leaves of Vicia faba, which had been previously supplied 

 with sugar as above, formed, without oxygen, 782.4 mg. of carbon dioxide and 

 724.6 mg. of alcohol, in twenty-five hours. The same number of similar leaves, 

 not previously supplied with carbohydrate, but otherwise treated in the same 

 way, gave off 256.8 mg. of carbon dioxide and 68.3 mg. of alcohol, in thirty 

 hours. In the first case the ratio of the amount of carbon dioxide to that of 

 alcohol produced is 100:92.6, and in the second case the corresponding ratio 

 is 100 : 26.5 It should be added here that alcohol elimination in the second 

 instance was confined to the first few hours of the experiment, before the limited 

 amount of plastic carbohydrates that was present had been exhausted. 5 



1 Lechartier, G., and Bellamy, F., Etude sur les gaz produits par les fruits. Compt. rend. Paris 

 69:356-360. 1869. Idem, De la fermentation des fruits. /Wd. 69 : 466-469. 1869. Idem, same title. 

 Ibid. 75: 1203-1206. 1872. Pasteur, Louis, Faits nouveaux pour servir a. la connaissance de la theorie 

 des fermentations proprement dites. Ibid. 75: 784-791. 1872. 



2 Godlewski, E., and Polzeniusz, F., Ueber Alkoholbildung bei der intramolecularen Athmung hoherer 

 Pflanzen. (Vorlaufige Mittheilung.) [Title also in Russian, text in German.] Bull. Int. Acad. Sci. 

 Cracovie 1897: 267-271. 1897. Idem, Ueber die intramoleculare Athmung von in Wasser gebrachten 

 Samen und uber die dabei stattfindende Alkoholbildung. [Title also in Russian and French, text in Ger- 

 man.] Ibid. 1901 : 227-276. 1901. Nabokich, A. J., Ueber die intramolekulare Atmung der hoheren 

 Pflanzen. Ber. Deutsch. Bot. Ges. 21: 467-476. 1903. Palladin, W., and Kostytschew, S., Anaerobe 

 Atmung, Alkoholgarung und Acetonbildung bei den Samenpflanzen. Zeitsch. physiol. Chem. 48: 214- 

 239. 1906. Idem, Ueber anaerobe Atmung der Samenpflanzen ohne Alkoholbildung. Ber. Deutsch. Bot. 

 Ges. 25: 51-56. 1907. Stoklasa, Julius, Ernest, Adolf, and Chocensky, Karl, Ueber die glykolytischen 

 Enzyme im Pflanzenorganismus. Zeitsch. physiol. Chem. 50: 303-360. 1906-1907. 



3 Pfeffer, W., Ueber intramolekulare Athmung. Untersuch. Bot. Inst. Tubingen 1:636-785. 1881- 

 1885. 



4 Palladin, W., Sur le role des hydrates de carbone dans la resistance a l'asphyxie chez les plantes superi- 

 eures. Rev. gen. bot. 6: 201-209. 1894. 



5 Palladin and Kostytschew, 1906, 1907. [See note 3, p. 218.] 



