HYDROTROPISM 487 



CzAPEK. 1895. Sitzungsber. Wiener Akad. 104, 337. 



CzAPEK. 1898. Jahrb. f. wiss. Bot. 32, 175. 



Darwin. 1881. Bewegungsvermogen d. Pflanzen. German ed. by Carus. 



Stuttgart. 

 DiETZ. 1888. Unters. bot. Inst. Tubingen, 2, 478. 

 Elfving. 1882, Bot. Ztg. 40, 257. 



Elfving. 1890. Commentationes var. Univ. Helsingfors. 

 Errera. 1892. Annals of Botany, 6, T,yT,. 

 Hegler. 1 891. Verb. d. Gesell. d. Naturforscher, 108. 

 JONSSON. 1883. Ber. d. bot. Gesell. i, 512. 

 JuEL. 1900. Jahrb. f. wiss. Bot. 34, 507. 

 KiHLMANN. 1883. Act. Soc. Fennicae, 13. 



Klercker. 1891. Oefvers. Vetensk. Akad. Forhandl. Stockholm, 10, 778. 

 LiDFORS. 1899. Ber. d. bot. Gesell. 17, 236. 

 [LiLiENFELD. 1905. Ber. d. bot. Gesell. 23, 91.] 



Mass ART. 1889. Arch, de Biologic (van Beneden and Bambeke), 9, 515. 

 MiYOSHi. 1894 a. Bot. Ztg. 52, I. 

 MiYOSHi. 1894 b. Flora, 78, 76. 

 MoHL. 185 1. Die vegetab. Zelle, p. 140. Braunschweig. (R. Wagner's Hand- 



worterbuch d. Physiologic.) 

 MoLiscH. 1883. Sitzungsber. Wiener Akad., Math.-nat. KL, I. Abt. 88, 897. 

 MoLiscH. 1884. Ibid. 90, III. 

 MoLiscH. 1889. Sitzungsanzeiger Akad. Wien. 



MoLiscH. 1893. Sitzungsber. Akad. Wien, Math.-nat.-Kl., I. Abt. 102, 423. 

 Muller-Thurgau. 1876. Flora, 59, 65. 

 Newcombe. 1902 a. Bot. Gaz. 33, 177. 

 Newcombe. 1902 b. Annals of Botany, 16,429. 

 [Newcombe and Rhodes. 1904. Bot. Gaz. 2,7 y 23. ] 

 Noll. 1892. Ueber heterogene Induction. Leipzig. 

 Pfeffer, quoted by Rothert. 1894. Flora, 79, 212. 

 Sachs. 1872. Arb. bot. Inst. Wiirzburg, i, 209. 

 [Sammet. 1905. Jahrb. f. wiss. Bot. 41, 611.] 

 Spalding. 1894. Annals of Botany, 8, 423. 



Steyer. 1 90 1. Reizkriimmungen bei Phy corny ces. Diss. Leipzig. 

 Van TiEGHEM. 1884. Traite de botanique. Paris. 

 VocHTiNG. 1888 a. Ber. d. bot. Gesell. 6, 167. 

 VocHTiNG. 1888 b. Bot. Ztg. 46, 501. 

 VbCHTiNG. 1890. Jahrb. f. wiss. Bot. 21, 285. 

 VocHTiNG. 1902. Bot. Ztg. 60, 87. 



WiESNER. 1878-80. Die heliotrop. Erscheinungen. (Denkschr. W. Akad.) 

 Wortmann. 1 88 1. Bot. Ztg. 39, 368. 



WORTMANN. 1883. Ibid. 41, 457. 



Wortmann. 1885. Ibid. 43, 193. 



LECTURE XXXVIII 



HAPTOTROPISM 



At the end of the preceding lecture we referred to curvatures which occurred 

 in the root as a consequence of contact stimulus. Such haptotropic or thigmo- 

 tropic movements are most conspicuously illustrated by tendril-bearing plants 

 (Darwin, 1876 a ; Pfeffer, 1885 ; Fitting, 1903 a) since these plants are pro- 

 vided with special organs or ' tendrils', whose function it is to attach themselves 

 to supports by haptotropic curvatures. Just as in the case of the twining 

 plants, the tendril-bearers are unable to stand erect by their own unaided efforts, 

 and hence they make use of any rigid bodies available as supports, whether these 

 be dead or alive. The attachment to the support is effected by a spiral winding 

 of a tendril round it. Since the tendrils are generally either leafless lateral 



