730 NOTES 



174. A. F. W. Schimper : Bot. Centr. 17, 1884. Id. Die epiphytische Vegetation 

 Amerika's, Jena, L888. Lierau : Engler's Jahrb. 9, 1888. 



IT"). Westermaier : Sitzb. Berlin, 1884. 



[175a. Cf. Note 173a.] 



[1756. Causes of medullaiion. The problem of the exact phyiogenetic origin of 

 pith, though doubtless of great interest, in my opinion, hardly lies within the scope 

 of the present work. The reader who may wish to pursue the subject, should consult 

 the following recent papers (in which further references will be found) : Bower : 

 A.B. 25 1911. Lang : A.B. 27, 1913.] 



176. A. Fischer : Ber. sachs. Akad. 1880. A. Koch : B.Z. 1884. 



177. VonMohl: B.Z. 1871. Thomas : P.J. 4. De Bary : Comp. Anat. pp 378 sqq. 



Zimmermann : Flora, 1880. Scheit : Jena. Zeitschr. 1883. Strasburger : I.e. [157], 

 pp. 102 sqq. 



178. The endodermis. Caspary : P.J. 1. Id. ibid. 4. Id. ibid. 6. Schwendener : 

 Abh. Akad. Berlin, 1882 (abstract in Ber. 1, 1883). Id. Sitzb. Berlin, 1890. Russow : 

 l.l.c [172]. Van Wisselingh : Versl. Med. Akad. Amst. 1884. De Vries : Maandbl. 

 Naturwet. 13, 1886. Id. B.Z. 1886, pp. 788 sqq. Strasburger : I.e. [157], pp. 105, 

 309, 344, 434, etc. H. Fischer : I.e. [172]. Kroemer : Bibl. Bot. No. 59, 1903. 

 The paper last cited contains many interesting data with regard to the structure of 

 endodermal layers, particularly with regard to the character of their cell-walls, 

 although the author considers much of the new terminology introduced by Kroemer 

 quite unnecessary. In the introduction, and again in his concluding remarks, 

 Kroemer states that his investigation was based on a hypothesis framed by A. 

 Meyer, to the effect that the cutinised or suberised strips in the walls of endodermal 

 cells (and also in the walls of the exodermal elements and " Aufzellen " of roots) 

 serve " in the first instance, to prevent as far as possible any diffusion, in the 

 substance of the walls, of dissolved mineral salts or reserve-materials." This hypothe- 

 sis does not appear to contain any novel idea. For all the numerous investigators 

 who have insisted upon the relative imperviousness of suberised endodermal walls 

 towards water, have undoubtedly regarded these walls as equally impervious to 

 all substances dissolved in water. The author himself, indeed, has expressed his 

 views on this point quite unequivocally in the second [German] edition of the 

 present work in the following words : "... the framework of suberised strips 

 the radial walls of the endodermis prevents any diffusion of water [through the 

 substance of the cell- wall] ; the dissolved materials conveyed by the vascular bundles 

 are, of course, similarly prevented from escaping through the radial walls." 



H. Miiller : B.Z. 1906. 



179. The literature dealing with the course and arrangement of vascular bundles 

 is very extensive. Cf. De Bary : Comp. Anat. Also the following Von Mold : 

 De structura palmarum, Munich, 1831. Id. in Von Martius : Icon plant, crypt. 

 Brasil. (tree-ferns). Unger : I.e. [172]. Nageli : Zeitschr. Wiss. Bot. Nos. 3 and 4. 

 Id. Beitr. Wiss. Bot. No. 1. Cramer in Nageli and Cramer: Pflanzenphysiol. 

 Unters. No. 3. Karsten : Abh. Berlin. Akad. 1847 (Palms). Hanstein : P.J. 1. 

 Id. Sitzb. Berlin. 1857. Von Ettingshausen : Die Blattskelette d. Dicot., Vienna, 

 1861. Hildebrand : Anat. Unters. ub. d. Stamme d. Begoniaceen, Berlin, 1859. 

 Geyler : P.J. 6 (Conifers). F. Schmitz : Das Fibrovasalsystem d. Piperaceen 

 (Inaug. -Dissert.), Essen, 1871. Vochting : Hanstein's Bot. Abh. 3 (Melastomaceae). 

 Id. P.J. 9 (Rhipsalideae). J. Weiss: Flora, 1876. Falkenberg : Vergl. Unters. 

 lib. d. Bau d. Vegetationsorgane d. Monokot., Stuttgart, 1876. Westermaier : 



