716 NOTES 



43. It is an interesting fact, that axial organs may develop a protective and 

 boring organ, resembling a root-cap, if they penetrate into the ground like roots. 

 The so-called geocalycoid Jungermanniaceae more appropriately termed " marsupi- 

 ferous," as suggested by Goebel illustrate this point. Here the apical region of each 

 archegonium-bearing shoot becomes transformed into a pouch; the shoot is posi- 

 tively geotropic and grows downwards into the soil, the archegonia, and later 

 the sporogonia, being stowed away inside the pouch. The remarkable structure of 

 the archegonial shoots of the Australian Aerobolbus unguiculatus has been described 

 by Goebel. Here the pouch may be as much as an inch in length ; so long as the 

 shoot is growing, the tip of the pouch is covered by a special boring and protective 

 organ, which is surprisingly like an ordinary root-cap. The apical region of the 

 pouch contains a subterminal meristematic zone, which is overlain by a cap-like 

 mass of resistant cells, that have ceased to divide. Cf. Goebel : Flora, 96, 1906, 

 pp. 155 sqq. G. Haberlandt : Flora, 1909. 



44. The classification of primary meristems employed in the text, was first 

 published in the author's Entwickelungsgesch. d. mech. Gewebesystems, where the 

 reasons for its adoption will also be found. In that treatise the protoderm is called 

 the "young epidermis," a term which no longer seems appropriate, since it is desirable, 

 in an anatomico-physiological treatise, to reserve the name epidermis for the primary 

 dermal layer in its fully developed condition. In the treatise mentioned, and in 

 the first [German] edition of the present work, the prosenchymatous primary meri- 

 stematic tissue is termed " cambium " in accordance with Niigeli's usage. At the 

 present day. however, the term " procambium," first introduced by Sachs, has 

 gained general acceptance, while most anatomists apply the name " cambium " 

 only to the meristem which effects the secondary growth in thickness of the stems 

 [and roots] of Dicotyledons and Gymnosperms ; in these circumstances, it seemed 

 preferable to employ the term procambium in accordance with general usage. 

 Finally, "fundamental meristem" (" ground-meristem ") is preferable to "funda- 

 mental parenchyma," so far as meristematic tissues are concerned, because the use of 

 the former term prevents any uncertainty, as to whether embryonic or permanent 

 tissues are under consideration. 



45. Hansen : Abh. Senck. 12, 1880. Heinricher : Sitzb. Wien, 78, 1878. Id. 

 ibid. 1881, and Rostowzew : Ber. 1894 [Gen. -Vers. -Hft.] (Ferns). Goebel: Biol. 

 Centr. 22, 1902. 



46. G. Haberlandt : I.e. [44]. Baranetzky, Ann. Sci. Nat., ser. VII., 1897. 



47. A very complete fist of the early literature dealing with the epidermis will 

 be found in De Bary's Comparative Anatomy. Note also : Von Mohl : Vcrmischte 

 Schriften, pp. 260 sqq. (cuticle). F. Cohn : De cuticula, Warsaw, 1850. Pfitzer : 

 P.J. 7, pp. 532 sqq. Id. ibid. 8, pp. 16 sqq. Westermaier : P.J. 14, pp. 43 sqq. 

 Hiller : P.J. 15, (petals). Solereder : Systematic Anatomy of the Dicotyledons 

 (Engl. ed. 1908). 



48. Pfeffer : Physiology of Plants (Engl, ed.), I. pp. 116-9, 243-4, etc. 



4!t. Unger : Sitzb. Wien, 44, 1861, pp. 205 sqq. According to linger, the ratio 

 between the (total) transpiration of a leaf of Digitalis purpurea and the evaporation 



from a freely exposed water-surface varies between - and 



J 1 1-4 6-9 



50. Wax. De Bary : B.Z. 1871, pp. 128 sqq. Wiesner : ibid. pp. 771 sqq. Id. 

 ibid. 1876, pp. 225 sqq. F. Haberlandt : Wissensch.-prakt. Unters. 2, 1877, p. 156. 

 Tschirch : Linnaea, N.F. 9, Nos. 3 and 4, 1881, pp. 147 sqq. Tittmann : P.J. 30. 



