COFFEA L. 5 



Microscopic Characteristics of the Seed: — (i) The seed-coat is 

 composed of several layers of collapsed, parenchymatous cells. Fre- 

 quently the structure is not very distinct but the cell-w^alls can be 

 seen here and there. The seed-coat includes numerous sclerenchy- 

 matous cells w^hich are invariably present in this genus. These cells 

 are about eight times as long as broad although there is some varia- 

 tion in proportionate w^idth. Sclerenchymatous cells are arranged 

 in approximation with their long axes parallel, and possess numerous 

 large oblique pits. They vary from 150 \i to 350 \i in length, and 

 taper bluntly, but are occasionally terminated by flat transverse 

 walls. Their walls are lignified. (2) The endosperm epidermis 

 and the one or two layers immediately beneath possess walls which 

 are evenly thickened. The remaining endosperm cells are parenchy- 

 matous, thick-walled structures with large pits which may be as 

 long as the width of the cell. In section, the cell-walls show a 

 distinct knottiness which is very characteristic. The cell-contents 

 consist chiefly of oil globules and proteid matter in addition to 

 normal cytoplasm. (3) The embryo is composed entirely of minute, 

 parenchymatous cells. 



Synonymy: — Hexepta Raf. Sylva Tellur. (1838) 164. — Lach- 

 nostoma Korth. in Nederl. Kruidk. Arch. 2 (1851) 201. 



Common Name: — Coffee. 



Geographical Distribution: — Tropical Asia; tropical Africa; by 

 introduction, throughout the tropics of the world. 



Number of Species: — Forty. 



Number of Economic Species: — Nineteen. 



History of the Genus Coffea: — Botanists of to-day agree that the 

 coffee-plant is indigenous to certain hilly regions of Abyssinia, of the 

 Soudan, of Guinea, and of Mozambique. Coffee has been used in 

 Ethiopia from the earliest times. Its use reached Abyssinia from 

 Ethiopia, and became known in Arabia probably during the thir- 

 teenth century. Arabia became the stepping-stone to its universal 

 consumption. It was Arabian coffee, shipped through the port of 

 Mocha, that resulted in the esteem for and the general use of the 

 term ''Mocha" for millions of tons of foreign-grown coffee. 



At that early period, Arabian traders were the most enterprising 

 in the world. They added coffee to other luxuries from Africa. 

 Since they were fortunately situated between Europe and Asia, 



