114 SEEDS. 



(58) Areca Nuts. 



The seeds of Areca. Catechu, Linn. (N.O. Palmee). 



The seed consists of a copious, horny, ruminate endosperm 

 covered by a thin brown seed-coat. The endosperm is white, 

 but is traversed in various directions by narrow, dark brown 

 lines which are infoldings of the inner layers of the seed-coat. 



The cells of the endosperm are very characteristic in appear- 

 ance. They are rather large, and are furnished with very thick 

 and highly refractive walls pierced by large pits. They contain 

 proteid matter which is coloured brown by iodine. 



The brown folds of the seed-coat, which produce the 

 ruminate appearance of the endosperm, consist of very dark 

 brown, polygonal cells with pitted walls. 



The cells of which the seed-coats are composed vary consider- 

 ably in appearance. The outer ones are elongated, moderately 

 thick- walled and more or less distinctly pitted and often exhibit 

 intercellular spaces of varying size. The cells of the inner 

 layers are more uniform in shape, being approximately 

 isodiametric ; their walls are more strongly lignified, and the pits 

 more numerous. 



The seed-coats are traversed by fibro-vascular bundles, the 

 debris of which frequently occur in the powder. 



At the base of the seed, where it is attached to the pericarp, 

 there is a tuft of coarse fibres, traversing a thin pale buff-coloured 

 coat that often covers the basal part of the seed. This coat is 

 the inner portion of the pericarp. The fibres consist of very 

 long, narrow, thick-walled, fibrous cells, the buff-coloured coat 

 of elongated empty pitted cells with thinner walls than those 

 of the outer cells of the seed-coat ; they may be detected in 

 the powdered seed. 



The diagnostic characters of powdered areca nuts are : 



(a) The characteristic cells of the endosperm with very 

 thick walls and large pits. 



(b) The remarkable sclerenchymatous cells of the seed- 

 coats. 



(c) Fragments of the ruminations, the cells of which have 

 thin pitted walls and red-brown contents. 



