12 
HISTOLOGY OF VEGETABLES. 
deposit on the internal surface of membrane ; examples, 
however, are not wanting in which the deposit has 
FIG. 4 . 
a, hair from the fornix of Anchusa italica. b, cells from the stem of a 
Balsam, c, tubercles from the hairs of Anchusa. d, ligneous cell of the 
Snake-wood, e f, cells from leaf of Pleurothallis. g h, vertical and hori- 
zontal sections of cells of a scale from the cone of Pinus Webbiana. 
taken place on the external surface, but these are rare in 
comparison with those illustrating the former mode of 
deposition. In the hairs of the fornix of Anchusa italica , 
a portion of one of which is represented by Fig. 4, A ; 
the outer surface of the thin violet-coloured membrane 
is studded with oval tubercles, some of which are shown 
in Fig. 4, c ; these were first pointed out by Schleiden. 
