Scrophulariaceae. 



395 



shoots have growth in thickness, but probably only to a 

 very limited degree. In Fig. 12 C two annual-rings are seen, 

 the last-formed is very excentric, the faet often being that 

 the most vigorous growth in thickness takes place on that 

 side of the stem which is opposite to a developing bud. 



Fig. 12. Castilleia pallida. 

 A and B, Transverse sections of the stem of the year's shoot; A is 

 taken from half-way up the stem, B from near the base. C, Trans- 

 verse section of a 2-year-old, persistent stem-base. D, A portion of 

 A, more highly magnified. (King Point.) [A, B and C about ^%; D 



about -30/^.) 



Fig. 12 D represents a part of A more highly magnified, the 

 epidermis and the outermost layer of the cortex is thick- 

 walled; the cortex is few-layered, its cells contain chloro- 

 phyll-grains; stomata occur in the epidermis. The endo- 

 dermis is only demonstrable by faint Casparian dots. 



