XIV 
Index . 
PAGE 
Figures. 38. Transverse section of leaf (see Fig. 23). Two growing-points are 
developing ; the anticlinal walls separating the groups of epidermal 
cells involved are plainly seen (Osborn) 503 
39. Portion of longitudinal section showing junction of leaf tissue and cell 
mass showing epideimal origin of latter. Cell mass developed 
stalk in which a ‘tracheide’ is seen (Osborn) .... 503 
40. Transverse section of leaf ; epidermis indicated by faint line. An 
irregular cell mass has formed, and the growing-point has begun to 
invaginate (Osborn) ....... . 505 
41. Portion of longitudinal section through cell mass, stalk (wdiich was 
accidentally bent), and tuber. ‘Vascular supply’ seen from its 
expansion in cell mass to cup of ‘ tracheides ’ around growing apex 
(x). Apex projecting into the chamber and seated on spherical mass 
of starchy tissue. The whole length of channel shown (Osborn) . 505 
42. Longitudinal section of adventitious growth on leaf in Fig. 20 B. Apex 
( x ) seen projecting into chamber ; extent of starchy tissue shown by 
faint line. Greater part of ‘ vascular supply ’ seen extending towards 
‘ leaflet’ (/) (which passes out of plane of section), but no ‘ leaflet’ 
bundle differentiated (Osborn) 505 
43. Detail of apex of tuber seen Fig. 41. Starchy tissue indicated by heavier 
outline to cells (Osborn) 506 
1. This figure is redrawn from Matlhaei’s Fig. 3, rectifying a mistake and 
adding, from her tables, two omissions (Smith) .... 522 
2. Reinke’s results. Curve A. Average of all results in Tables I to VIII. 
B. Average of all results except those obtained after the plant had 
been once exposed to 16 units of light (Smith) .... 533 
