LECT. VII.] ANATOMY OF STEMS. 295 



ous bundles appear like spots, which are in some 

 instances of a dark colour, and in others white, 

 dispersed over a white or a green ground, in 

 the order just described. The epidermis adheres 

 closely to the parenchyma beneath it ; and in 

 some plants of this class, the greater density of 

 the cellular substance at the circumference gives 

 the appearance of a bark, which is never, how- 

 ever, present in this description of stem. Such 

 is the general character, and the distribution 

 of the parts, in what may be termed the lig- 

 neous solid monocotyledonous stems* ; but when 

 they have more of an herbaceous character, such, 

 for example, as the scape of Great yellow Gar- 

 lick, Allium Moly, there are no indurated lig- 

 neous cords ; but the vessels run in the midst of 

 longitudinal layers of condensed cellular matter, 

 and in a transverse section appear as white dots 

 forming a circle round the central cells, which are 

 generally much larger than those of the circumfe- 

 rence, and assume in some degree the aspect of 

 a pith *}- ; so that in the longitudinal section, the 



* The student, who cannot procure the stem of a Palm, 

 may attain an excellent idea of the internal structure of the 

 solid monocotyledonous stem in the flower-stalk of the Tigri- 

 dia pavonia, which is now very common in the stoves of the 

 London florists and nurserymen; or in that of the Typha 

 latifolia, not unfrequent in ditches, flowering in July. 



f Vide Plate 5, fig. 5. A. a transverse slice of the scape of 

 Allium Moly, nearly of the natural size. 



u4 



