512 TRANSFORMATION OF ENERGY 



Bibliography to Lecture XXXIX. 



BATALIN. 1873. Flora, 56, 450. 



BRUCKE. 1848. Archiv f. Anat. u. Physiol. Ostwald's Klassiker, No. 95. 



BURGERSTEIN. 1902. Bewcgungsersch. d. Perigonblatter von Tulip a u. Crocus 



(Jahresbericht Erzherzog Rainer Gymnasium. Vienna). 

 DARWIN. 1881. Das Bewegungsvermogen d. Pflanzen (CARUS.) Stuttgart. 

 FISCHER, ALFR. 1890. Bot. Ztg. 48, 673. 

 FITTING. 1903. Jahrb. f. wiss. Bot. 38, 545 [and 39, 424]. 



HANSGIRG. 1893. Physiologische und phycophytologische Untersuchungen. Prag. 

 [HENSEL. 1905. Nebraska University Studies. V. No. 3.] 

 HILBURG. 1 88 1. Unters. bot. Inst. Tubingen, i, 23. 

 JOST. 1895. Jahrb. f. wiss. Bot. 27, 403. 

 JOST. 1898. Ibid. 31, 345. 

 NOLL. 1892. Heterogene Induktion. Leipzig. 

 OLTMANNS. 1895. Bot. Ztg. 53, 31. 



PANTANELLI. 1900. Atti soc. dei Naturalisti. IV, 2. Modena. 

 PFEFFER. 1873. Physiologische Untersuchungen. Leipzig. 

 PFEFFER. 1875. Periodische Bewegungen. Leipzig. 

 SACHS. 1863. Flora, 46, 449. 



SCHILLING. 1895. Einfl. von Bewegungshemmungen auf Arbeitsleistung. Jena. 

 SCHWENDENER. 1897. Sitzungsber. Berliner Akad. 228. 



SCHWENDENER. 1898. Ibid. 176. 



SCHWENDENER and KRABBE. 1892. Abh. Berl. Akad. 



SCHUBLER. 1873. Die Pflanzenwelt Norwegens. Christiania. 



[SEMON. 1905. Biol. Centrbl. 25, 241.] 



STAHL. 1897. Bot. Ztg. 55, 71. 



VINES. 1889. Annals of Bot. 3. 



VOCHTING. 1888. Bot. Ztg. 46, 501. 



VOCHTING. 1891. Ibid. 49, 113. " 



[WiEDERSHEiM. 1904. Jahrb/f. wiss. Bot. 40, 230.] 



LECTURE XL 

 MOVEMENTS RESULTING FROM SHOCK 



IN the last lecture, in which we treated of nyctitropic movements, we had 

 frequent occasion to mention Mimosa, but we must not lose sight of the fact that 

 this plant is sensitive to other stimuli as well as to alterations of light and tem- 

 perature. In fact Mimosa exhibits another sensitivity much more prominently 

 than it does nyctitropism ; a gentle shaking of the leaf is sufficient to induce at 

 once a very characteristic change in position. This new rest position corre- 

 sponds exactly with the sleep position, for the primary petiole droops consider- 

 ably and the secondary petioles move forwards almost parallel with the long axis 

 of the primary petiole, the leaflets folding together in pairs and, at the same 

 time, bending obliquely forwards. In spite of their great superficial similarity 

 the two movements are in reality quite distinct and arise in quite different ways. 

 The reaction induced by shock differs further from the sleep movement in the 

 rapidity with which it is carried out ; a few seconds are sufficient for its execution. 

 On account of the rapidity with which the response takes place, the movement of 

 the Mimosa leaf is one of those with which we have been longest acquainted 

 in plant life, a movement which, owing to its rapidity alone, has been compared 

 with the responses to stimuli exhibited by animals, and which was always looked 

 upon as a genuine reflex action even at a time when the absence of sensitivity 

 in plants was regarded as one of the distinctions between plants and animals. 

 These movements in the ' Sensitive plant ', in addition to geotropic movements, 



