152 SEEDS 



in this state are brought chiefly from Lagos to Sokoto, Kano, and 

 Timbuctoo, whence they are distributed to other parts of Africa. 

 The fresh seeds are also occasionally exported, but more commonly 

 the kernels are separated into the two large fleshy cotyledons and 

 dried, during which the white or crimson colour changes to a dull 

 reddish brown. 



Description. Dried cola seeds, as commonly seen in this country, 

 consist of the kernels only of the seeds, sometimes entire, but more 

 often separated into the two cotyledons. Externally, they have a 

 dull dark brown or reddish brown colour ; internally they are usually 

 somewhat paler. They are hard and solid, and exhibit, when cut, 

 a perfectly uniform section, no mucilage glands being observable. 

 They vary in length from about 2 to 5 cm., and are rather less in 

 breadth and in thickness. In shape, too, they exhibit considerable 

 differences, being frequently flat on one side and curved on the other, 

 or wedge-shaped or irregularly six-sided. A shallow furrow encircles 

 the kernel, dividing it into two cotyledons ; transverse to this furrow 

 at one end of the seed a distinct cleft may be found, partially separating 

 each cotyledon into two portions. Complete kernels may easily be 

 separated into their constituent cotyledons, and the small radicle 

 will be found towards the bottom of this transverse cleft. 



Fresh cola seeds have a bitterish astringent taste, which is scarcely 

 perceptible in the dry seed ; the latter are also destitute of any marked 

 odour. 



The student should observe 



(a) The two large fleshy cotyledons and small radicle, 



(b) The absence of seed-coats, the drug consisting of the kernel 



only. 



Constituents. The most important constituents of kola seeds 

 are caffeine (1 to 2-5 per cent.), kolatin (0-75 per cent, mostly combined 

 with the caffeine), and traces of theobromine. They also contain 

 kolatein, an oxydase enzyme, fat, sugar, and abundance of starch. 



Kolatin, C 8 H 8 4 , is crystalline, slightly soluble in water, but readily in alcohol. 

 During the drying of the seeds it is converted by the oxydase into kola -red, 

 a substance allied to the phlobaphenes, which is therefore present in the dried 

 drug to the exclusion of kolatin and imparts to it the characteristic colour. 

 If, however, the seeds are boiled and the oxydase thus destroyed, the dried 

 seeds retain the colour of the fresh and contain the kolatin. The fresh seeds 

 may also be preserved by beating them into a pulp with an equal weight of 

 loaf sugar. 



Kolatein is also crystalline, soluble in alcohol and in hot water; it has 

 not yet been completely investigated. 



Kolanin, a reputed constituent of the seeds, appears to be a mixture of kola- 

 red and caffeine. 



