APPENDIX. BOOK I. g^y 



Page 29. With regard to the growth of the cell- wall by intussusception, see note 

 above referring to page 19. 



Page 30. With regard to the growth in thickness of the cell-wall, see the note 

 referring to page 19. 



Page 36, 1 6th line from the top: for * molecules' read 'micellae.* 



Page 37. Protoplasm. According to Schmitz (Unters. ueb. die Struktur des Pro- 

 toplasmas und der Zellkerne, Sitzber. d. niederrhein. Ges. in Bonn, 1880), a net-work 

 of fine fibres exists in protoplasm, the meshes of which are occupied by a homogeneous 

 fluid : the net-work readily stains with haematoxylin, but the fluid remains colourless. In 

 the endoplasm, more particularly, a greater or smaller number of fine granules, termed by 

 Hanstein microsomata, which stain deeply with haematoxylin, are present. (See also 

 Frommann, Beob. iib. Structur und Bewegungserscheinungen des Protoplasma, Jena, 1880. 

 —Hanstein, Das Protoplasma, Heidelberg, 1880: id., Einige Zuge aus der Biologic des 

 Protoplasmas, Botanische Abhandlungen, IV. 2, 1880. — Strasburger, Zellhaute, 1882.— On 

 the Chemistry of Protoplasm, see Reinke, in Unters. aus dem Bot. Lab. der Univers. 

 Gottingen, II, 1881.) 



Page 44. The Nucleus. Schmitz has detected one or more nuclei in a number of 

 Thallophytes {Batrachospermum moniliforme, Codium, Faucheria, Caulerpa, Conferva, Gon- 

 grosira, Schizogonium, Monostroma, Chlamydomonas, Chroolepus, Saprolegnia, Mucor, Sac- 

 charomyces, Mycoderma, Oidium, Exoascus, Peziza, Morchella, Ascobolus, Myxomycetes, etc. • 

 (Sitzber. d. niederrhein. Ges. in Bonn, 1879 and 1880): he believes that the Phycochro- 

 maceae and the Schizomycetes are the only plants in which no nucleus is present. 



With regard to the function of the nucleus, it does not appear that it regulates the 

 process of cell-division. Strasburger is of opinion (Bau und Wachsthum der Zellhaute, 

 1882, p. 241) that it is of importance in the 'nutrition of the cell, more especially as regards 

 the formation of proteids. 



With regard to the structure of the nucleus, see page 18. 



Chemically the nucleus consists of a substance termed nucle'in, to which Miescher has 

 given the formula C29 H49 Ng P3 O22. (See Hoppe-Seyler, Physiologische Chemie ; also 

 Zacharias, Die chemische Beschaffenheit des Zellkerns, Bot. Zeitg. 188 1.) 



Page 48. On the development of chlorophyll-granules, see Mikosch, Unters. lib. 

 die Entstehung der Chlorophyllkorner, Sitzber. d. k. k. Akad. in Wien, LXXVIII, 1878. 



Page 49. Structure of chlorophyll-granules. Pringsheim has observed (Ueb. Licht- 

 wirkung und Chlorophyllfunction in der Pflanze, Jahrb. f. wiss. Bot., XII, 1881) that 

 when green parts of plants are treated with dilute acids or with warm water the colouring- 

 matter exudes in viscid drops, the colourless basis remains behind and presents a trabecular 

 structure in the interstices of which the colouring-matter was previously contained. 



Page 49-51. Crystalloids and Aleurone-grains. On Rhodospermin, see note on 

 page 289. — Schimper, Unters. iib. die Proteinkrystalloide der Pflanzen, Strassburg, 1879 : 

 id., Ueb. die Krystallisation der eiweissartigen Substanzen, Zeitschr. fiir Krystallographie, 

 1880. — Vines, On the Proteid Substances contained in the Seeds of Plants, Journal of 

 Physiology, III, 1881. — Julius Klein, Die Krystalloide der Meeresalgen, and Die Zellkern- 

 Krystalloide von Pinguicula und Utricularia, Jahrb. f. wiss. Bot. XIII, 1881. 



An aleurone-grain consists of a mixture of proteids, some of which are soluble in 

 water, and others in either saturated or dilute solution of common salt; the former 

 belong to the chemical group of peptones, the latter to the globulins. In some cases the 

 grain does not dissolve in salt solution ; this is probably due to a chemical alteration of 

 the globulins into albuminates. The crystalloids consist chemically of globulins or of 

 altered globulins (albuminates). 



Page 57 et seq. In the account of the growth of starch-grains the word * micella' is 

 to be substituted for 'molecule' (see Bk. Ill): it is also preferable to use the word 

 ' hilum ' instead of ' nucleus.' 



With reference to the mode of growth of starch-grains, it appears from Schimper's 

 observations (Unters. iib. das Wachsthum der Starkekorner, Bot. Zeitg. 1881) that they 



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