FRANSERIA DUMOSA. 



17 



as follows: The epidermis has a relatively thin cuticle. At a distance of 

 1.5 cm. from the tip its contents are colorless, but in the older parts a dark 

 purple pigment is present. As previously mentioned, multicellular hairs 

 and other hairs occur; these are to be found most abundant, perhaps, where 

 no pigment is present in the epidermis. The secretion from these hairs, 

 which is soluble in chloroform and ether, is so copious as to nearly sub- 

 merge them, and covers the stem as far as the location of cork. The cortex 



Fig. 7. — Franseria dumosa: A, 

 transverse section of stem 1.23 

 mm. in diameter, showing 

 general distribution of chloro- 

 phyll; 5,detail of A, to show 

 character of cortical chloren- 

 chyma; C, secreting hair from 

 young part of stem, to show 

 presence of chlorophyll, which 

 is indicated by stippling, on 

 periphery of cells. The cells 

 of the epidermis do not con- 

 tain chlorophyll. 



in stems 1.23 mm. in diameter and 5 cm. from the tip is composed of four 

 well-defined tissues, which, enumerated from without, are collenchyma, 

 parenchyma, hard bast, and soft bast. The collenchymatous and the par- 

 enchymatous portions are chlorophyll-bearing; some chlorophyll may also 

 be found in the ground-tissue between the hard bast and the cambium. 

 The parenchyma exterior to the hard bast contains chlorophyll and is made 

 up of cuboid cells with large intercellular spaces. 



