COCILLANA 383 



the mahogany wood, which is considered one of the most durable 

 and valuable of cabinet woods. The true mahogany is obtained from 

 Swietenia Mahogoni, a native of tropical America and formerly very 

 abundant in Jamaica; now, however, probably all of the mahogany 

 wood comes from Central America. It is cultivated to some extent 

 in Florida and California as an ornamental tree. Other genera of 

 this same family yield a wood which is substituted and sold for ma- 

 hogany. There are quite a number of timbers, which are obtained 

 from plants entirely unrelated to the Meliaceae, that are also sold in 

 commerce as mahogany. 



In the Meliaceae the tracheae always have simple perforations, 

 except when adjoining parenchyma cells, they possess bordered 

 pores. The wood fibers have large lumina and are usually marked 

 by simple perforations and occasionally have septate transverse 

 walls. One of the marked characteristics of these plants is the 

 presence of secretory cells in the pith, cortex and leaves; in tho 

 latter they give rise to transparent dots, which are readily apparent* 

 on holding the leaves to the light. 



The .epidermal cells are usually modified to mucilage. Bast 

 fibers and stone cells occur in isolated groups in the pericycle, occa- 

 sionally there being a ring of stone cells also in this region. Calcium 

 oxalate is secreted in the form of rosette aggregates or solitary 

 crystals. Both glandular and non-glandular hairs occur in a number 

 of specific forms. 



Cocillana. The bark of Guarea Rusbyi (Fam. Meliaceae), a 

 tree indigenous to the eastern Andean slope in Bolivia. It is used 

 by the natives as an emetic and has been introduced into medicine 

 in the United States to some extent as an expectorant, it being said 

 to resemble ipecac in its action on the respiratory organs. 



Description. In flattened or somewhat transversely curved 

 pieces from 5 to 12 cm. in length, 1 to 3 cm. in width, and 3 to 5 mm. 

 in thickness; externally grayish-yellow or -brown with whitish 

 patches of a lichen, roughly and unevenly fissured, having longitu- 

 dinal furrows and occasionally transverse fissures; inner surface 

 grayish-yellow, coarsely striate and often roughly fibrous from 

 detached strands of bast fibers; fracture coarsely granular in the outer 

 bark, and splintery fibrous in the inner bark; transverse surface with 

 thick, light reddish-brown periderm, having numerous - yellowish- 

 white stone cells, inner bark tangentially, finely striate; odor slight; 

 taste somewhat astringent, unpleasant and slightly nauseous. 



Inner Structure. (Fig. 168.) Periderm of several layers of 

 primary and frequently even secondary cortex, between which are 



