948 APPENDIX. BOOK I. 



grow by apposition and not by intussusception. He is led to the conclusion that a starch- 

 grain is a sphero-crystal, built up of prismatic crystalloids. (By a * crystalloid ' is meant here 

 and elsew here a crystal which is capable of swelling-up.) This conclusion is supported by 

 Meyer {ibid.), and by Strasburger (Bau und Wachsthum der Zellhiiute, 1882), but is severely 

 criticised by Niigeli (Unters. lib. das Wachsthum der Starkekorner, Bot. Zeitg. 188 1). 



It is known that when starch-grains are formed in parts of plants exposed to light, 

 they arise in connexion with the chlorophyll-granules. Schimper has made the interesting 

 observation (Bot. Zeitg. 1880; also Researches upon the Development of Starch-grains, 

 Quart. Journ. Micr. Sci., 1881) that when they are formed in parts of plants not exposed 

 to light they arise in connexion with small masses of protoplasm which he terms ' starch- 

 forming corpuscles' {Starkebildner). That they are closely related to the chlorophyll- 

 granules is shown by the fact that if cells containing starch-forming corpuscles are exposed 

 to light, the corpuscles turn green and become in fact chlorophyll-granules. Errera 

 suggests the name ' amidoplasts ' for these bodies. 



Schimper observed that the point of attachment of the starch-grain to the chlorophyll- 

 granule or starch-forming corpuscle lies in the line of the long axis of the grain, — that is, 

 in the line of most rapid growth, — and at its broader end ; the hilum is near the free 

 narrow end of the grain. These facts afford a strong argument in favour of the growth of 

 the grain by apposition. 



Page 64, line 9 from the top. For * erecta ' read ' cvecta.^ 



Page 65. On the distribution of calcium carbonate, see Molisch, Ueber die Abla- 

 gerung von kohlensaurem Kalk im Stamme dicotyler Holzgewachse, Sitzber. d. k. k. Akad. 

 in Wien, LXXXIV, 1881. 



Page 68. Cystoliths. See also Richter, Beitr. zur genauern Kenntniss der Cysto- 

 lithen, etc., Sitzber. d. k. k. Akad. in Wien, LXXVI, 1877, and Melnikoff, Unters. iib. das 

 Vorkommen des Kchlensauren Kalkes in Pflanzen, Diss. Inaug., Bonn, 1877. 



Page 70. The statement made here with reference to the formation of the endo- 

 sperm in the embryo-sac of Phanerogams is not quite accurate : compare p. 585. 



For a more complete account of the Morphology of the Tissues, see de Bary, 

 Vergleichende Anatomic der Vegetationsorgane der Phanerogamen und der Fame, 1877. 



Page 77. Leitgeb has found (Die Athemoffnungen der Marchantiaceen (Sitzber. 

 d. k. k. Akad. in Wien, LXXXI, 1880) that the hypodermal chambers of these plants is not 

 formed, as described in the text, by the separation of the epidermal cells from the sub- 

 jacent tissue : these chambers make their first appearance as pits which become overgrown 

 by the epidermal cells which form their limits, and the communication between the cavity 

 of the pit and the external air may be continuous from the beginning, or the pits may 

 become completely closed in by the overgrowth of the surrounding epidermal cells, the 

 communication being restored on the development of the stoma. In both cases the cells 

 forming the stoma are not derived from a single mother cell; in the former case the 

 stomatal cells are formed by the cutting off of contiguous segments from the cells bounding 

 the opening ; in the latter, by the cutting off of segments in a similar manner from the 

 cells lying over the centre of the chamber, and by the subsequent separation of these 

 segments so as to form an opening between them. The stomatal cells may then divide so 

 as to form a series of superposed cells, and thus the complex stoma of Mar chant ia, for 

 example, is produced. 



Page 86. On the development of laticiferous vessels, see Schmalhausen, Beitr. z. 

 Kenntniss der Milchsaftbehalter der Pflanzen, M6m. de TAcad, imp. de St. Petersbourg, 

 XXIV, 1877; also Scott, The Development of Articulated Laticiferous Vessels, Quart. 

 Journ. Micr. Sci., 1882, and Schmidt. Bot. Zeitg., 1882. 



Page 88, line 2 from the bottom. The statement in the text that sieve-tubes occur 

 only in the fibro-vascular bundles is not correct. Scattered bundles of them occur in the 

 stems of many Dicotyledons and Monocotyledons ; in the periphery of the pith in Solanum 

 tuberosum, Dulcamara, species of Nicotiana, Datura, and Cestrum, in many Campanulaceae, 

 and among Composites in Gundelia Tournefortii, and in the genera Lactuca, Scor%onera^ 



