412 SCIENTIFIC AND APPLIED PHARMACOGNOSY 



Vermont, and also in New York, Ohio and Indiana. The sugar is 

 obtained at the beginning of spring when the growth of the buds and 

 new leaves are about to develop. The trees are tapped about 1 or 2 

 M. from the ground, a tubular spile being driven into the wood and 

 through which the sap flows into suitable receptacles. The sap is 

 then refined and enters the market either as a syrup or a loaf sugar; 

 the most palatable product, however, is that which is not refined and 

 in which the syrup and crystals retain their natural yellow color. 

 The yield per tree is from 1.5 to 3 K. annually, and if the process is 

 properly conducted, there is no damage to the trees. A small 

 amount of sugar is also obtained from the black sugar maple 

 (Acer saccharum nigrum) and the silver or white maple (Acer 

 saccharinum). 



Among the chief histological characters of this family the fol- 

 lowing may be mentioned. The pericycle consists of either isolated 

 groups of bast fibers, or a composite ring of sclerenchyma. The 

 tracheae usually have narrow lumina and simple pores; the wood 

 fibers also possess simple pores. Mucilaginous epidermal cells occur 

 in a number of species, and in Acer Pseudo-platanus the epidermal 

 cells, on the lower surface of the leaves, are modified to papillae. 

 Calcium oxalate occurs in the form of solitary crystals or large rosette 

 aggregates. The non-glandular hairs are either unicellular or uni- 

 seriate. The glandular hairs are small and of a number of specific 

 forms. 



ACER SPICATUM. Mountain Maple Bark. The dried bark of 

 Acer spicatum (Fam. Aceracese), a shrub growing in the mountainous 

 sections of the United States. The bark has for years been substi- 

 tuted for that of Viburnum Opulus. 



Description. In somewhat transversely curved pieces, attaining 

 a length of 20 cm.; bark about 1 mm. in thickness; outer surface 

 dark grayish-brown with numerous elliptical brown lenticels and 

 grayish patches of foliaceous lichens with their small brownish-black 

 apothecia; inner surface light brown, obscurely longitudinally striate, 

 and with usually more or less of a thin layer of wood adhering; frac- 

 ture short-fibrous, uneven; odor slight; taste astringent, bitter. 



INNER STRUCTURE. See Fig. 176. 



Powder. Grayish-brown, consisting of numerous coarse fibrous 

 fragments; bast fibers having strongly lignified walls and associated 

 with crystal fibers, each cell containing a monoclinic prism of calcium 

 oxalate about 0.010 mm. in diameter; numerous fragments of yellow- 

 ish-brown or dark brown cork cells; calcium oxalate either in paren- 

 chyma cells or isolated, mostly in monoclinic prisms varying from 



