NOTES 751 



.">4.~>. L. Linsbauer : Wiesner Festschrift, Vienna, 1!)08. 



346. Borzi (Rivista di. Sci. Biol. 4, 1899) states, as an objection to the author's 

 theory, that the leaves of Mimosa respond when the roots are injured, although the 

 latter contain no secretory sacs. According to the author's own observations, 

 however, this statement only applies to the lateral roots, the characteristic secretory 

 elements being undoubtedly present in the leptome of the main root; a single 

 experiment provides a complete answer to Borzi's objection. A vigorous young 

 plant of Mimosa pudica was removed from its pot, and its root-system immersed in 

 a vessel tilled with tap-water, after the adhering soil had been carefully washed away 

 as far as possible. On the following day (T = 22 C), when the plant had completely 

 recovered, several lateral (secondary) roots were carefully cut off, one at a time, 

 with scissors (including the uppermost lateral root, the insertion of which was only 

 2-5 cm. from the lowermost leaf) ; no response resulted, even when a whole bunch 

 of rootlets were severed at once. When, however, the mam root was cut across, 

 at a point about 3 -5 cm. below the lowermost leaf, all the leaves, except the two upper- 

 most, responded immediately. Response on the part of the leaves to traumatic 

 stimulation of a root is therefore evidently correlated with the presence of secretory 

 sacs in the latter, and failure to respond with the absence of these cells. 



Dutrochet obtained an immediate response on pouring sulphuric acid over the 

 root-system (the author's erroneous statements regarding this point are corrected 

 by Borzi), the explanation, no doubt, being that not only the lateral roots, but also 

 the main root suffered corrosion. 



A further argument advanced by Borzi against the author's theory is based on 

 the fact that transmission of stimuli takes place in the allied genus Neptunia, in which 

 both Borzi and Fitting failed to find any secretory sacs. The author has so far 

 had no opportunity of examining Neptunia oleracea himself; but in view of his 

 experiences with other Leguminosae, he remains sceptical regarding the absence 

 of secretory sacs in the genus. 



347. Eichler : Sitzb. Berlin, 1886. Kraus : Sitzb. phys.-mediz. Ces. Wiirzb. 

 1899. Strasburger : P.J. 43, 1906. Kranzlin : Ber. 24, 1906. 



348. Sachs : Lectures, pp. 155-6. 



349. Nageli : Beitr. 1, 1858, p. 4. Sanio : B.Z. 1863, pp. 357 sqq. Id. P.J. 

 9, 1873. Velten : B.Z. 1875, p. 811. G. Haberlandt : Entw. d. mech. Gewebe- 

 systems, 1879, pp. 39 sqq. Id. Ber. 1886. Strasburger : Bau u. Wachst. d. Zell- 

 haute, 1882, pp. 39 sqq. Id. Leitungsbahnen, Jena, 1891. Krabbe : Das gleitende 

 Wachstum, Berlin, 1886. Mischke : Bot. Centr. 44, 1880. Kriiger : B.Z. 1802. 

 Raatz : P.J. 23, 1892. Wieler : Ber. 1886. Nordhausen : Funfstuck's Beitr. 2, 

 1898. Schoute : Verh. Akad. Anist., ser. II., 1902. 



350. Th. Hartig : Forstliche Kulturpflanzen, Berlin, 1857. Hanstein : CJnters. 

 iib. d. Bau u. d. Entw. d. Baumrinde, Berlin, 1853. J. Moller : Anat. d. Baum- 

 rinden, Berlin, 1882. Schwendener : Mechanisches Prinzip, pp. 143 sqq. Strasburger: 

 Sitzb. Berlin, 1890. Id. Leitungsbahnen. 



351. Th. Hartig : I.e. [350]. Id. B.Z. 1859. Sanio : B.Z. 1863. Wiesner : 

 Die Rohstoffe d. Pflanzenreiches, 2nd ed. Leipzig, 1902, Ch. XVII. (Timber, by 

 Karl Wilhelm). J. Moller : Denkschr. Wien., 1876. De Bary : Comp. Anat. pp. 

 475 sqq. Strasburger : Leitungsbahnen (contains a large number of fresh observa 

 tions on the structure of secondary wood). 



352. The classification of the various components of the secondary wood employed 

 in the present work is based on that of Sanio, which has not yel been surpassed for 



