AEROBIC RESPIRATION 525 



twenty days. Further details are given in the works mentioned. Similar curves 

 have been obtained with cultures of mould-fungi. 



Similarly the respiratory activity attains a maximum during the expansion of 

 the buds; and not only becomes relatively feebler in the adult leaves but 

 gradually diminishes as they grow older \ Owing to the rapid development and 

 short duration of flowers, their respiratory curves exhibit a rapid rise and fall, the 

 maximum usually coinciding with the opening of the flower 2 . A mass of flowers 

 occupying the space of one cubic centimetre may consume in one hour during the 

 period of most active respiration ^-i c.cm of oxygen ; the flowering spadix of 

 Arum italicum may use as much as thirty times its own volume per hour, whereas 

 before and after opening it consumes less than one-third its volume per hour 3 . 

 It has frequently been shown that the respiratory activity decreases during the 

 ripening of fruits, tubers, bulbs, &c. *, and a similar diminution occurs in bulbs, 

 tubers and trees during winter, although respiration does not entirely cease until the 

 temperature falls below 10 to i2C. 



The tables given by Garreau and Aubert, contain further examples of specific 

 respiratory activities 5 . According to Aubert, i gramme weight of living leaves and 

 stems consumes at i2-i3C. of oxygen per hour: Cereus macrogonus 3, Picea 

 excelsa 44, Faba vulgaris 97, Triticum sativum 291 cc. Shade plants respire 

 in general comparatively feebly, probably in adaption to their habitat (Sect. 62), 

 and according to Freyberg" the same is the case in swamp- and water-plants. 



Historical. After Malpighi had shown the necessity of air for germination, 

 Scheele proved that during this process oxygen (fire-air) was consumed and carbon 

 dioxide (fixed-air) produced, as in the respiration of animals. Further researches 

 were made in connexion with the assimilation of carbon dioxide by Ingenhousz and 



1 De Saussure, Rech. chim., 1804, p. :oo; Garreau, Ann. d. sci. nat., 1851, Hi. sen, T. xvr, 

 p. 279; Deherain et Moissan, ibid., 1874, v. sen, T. XIX, p. 327; Borodin, Bot. Jahresb., 1876, 

 p. 922, and Bot. Centralbl., 1894, Bd. LVIII, p. 374; Mangin, Bull. d. 1. Soc. Bot. d. France, 1886, 

 p. 185 ; Aubert, Rev. gen. d. Bot, 1892, T. iv, p. 352. 



2 De Saussure, Ann. d. chim. et d. phys., 1822, T. xxi, p. 292 ; Lory, Ann. d. sci. nat., 1847, 

 iii. sen, T. vill, p. 161 ; Cahours, Compt. rend., 1864, T. LVIII, p. 1206; Bonnier et Mangin, 

 Ann. d.'sci. nat., 1884, vi. sen, T. xvni, p. 35- 



3 Garreau, Ann. d. sci. nat, 1851, iii. sen, T. xvi, p. 254. Cf. also G. Kraus, Ober die 

 Bliithenwarme von Arum italicum, 1884 (Abh. d. Naturf.-Ges. z. Halle, Bd. XVI). 



* Fruits: de Saussure, Ann. d. chim. et d. phys., 1821, T. XIX, p. 163, 338; Cahours, Compt. 

 rend., 1864, T. XXI, p. 496; Laskovsky, Versuchsst, 1878, Bd. xxi, p. 195. Tubers: Nobbe, 

 Versuchsst, 1865, Bd. vn,p. 451 ; Heintz, Jahresb., 1873, p. 358; Miiller-Thurgau, Landw. Jahrb., 

 1885, Bd. XIV, p. 857; Stich, Flora, 1891, p. 15; Richards, Annals of Botany, 1896, Vol. X, 

 p. 531. 



s Garreau, Ann. d. sci. nat, 1851, iii. sen, T. xv, p. 33; Aubert, Rev. gen. d. Bot, 1892, 



T. iv, p. 375. 



Freyberg, Versuchsst, 1879, p. 463. Further examples of specific respiratory activity are 

 given in the following works : Jonsson, Compt. rend., 1894, T. CIX, p. 440 (Mosses) ; Jumelle, Rev. 

 gen de Bot., 1892, T. iv, p. na (.Lichens); Diakonow, Ben d. Bot. Ges., 1886, p. 3; Bonnier et 

 Mangin, Ann. d. sci. nat, 1884, vi. sen, T. XVII, p. 209 (Fungi); Hesse, Zeitschr. f. Hygiene, 1893, 

 Bd. xv, p. 183 (Bacteria) ; Mangin, Bull. d. 1. Soc. Bot. d. France, 1886 (Pollen-tnbes) ; Palladm, 

 Rev. gen. d. Bot, 1893, T. V, p. 368 (Normal and Etiolated Plants). 



