cusso. Kousso. 213 



calyx lobes. Stoma ta and trichomes are numerous. 

 The latter are of two kinds, the one simple, pointed, 

 single-celled, thick- walled, on the leaves, large; on the 

 calyx smaller. The other variety is short, bearing 

 glands, consisting of small many-celled or large single- 

 celled heads, supported on short pedicles. On the bracts, 

 a layer of palisade cells lies beneath the epidermis. The 

 mesophyll consists of star-shaped cells, with large inter- 

 cellular spaces. The peduncle bears an epidermis of 

 finely striated cells. The elongated parenchymatic cells 

 within, enclose agglomerated crystals of calcium oxalate. 

 A few tracheids are also present. The tissue of the 

 anthers is recognized by the regularity of the arrange- 

 ment of the cells and the reticulate thickenings of the 

 walls. The surface of the stigma is papillous. 



Powder. — The elements of the powder are numer- 

 ous; the most predominant being the trichomes, which 

 vary greatly in size. Spiral and pitted vessels from the 

 peduncle are frequent. The characteristic, usually four- 

 celled, glands are less often met with. For the rest, 

 stone cells from the peduncle, calcium oxalate crystals 

 from the leaf parenchyma, and epidermal tissue, are of 

 little importance. Pollen grains, if present in large 

 numbers, indicate the admixture of male flowers; their 

 occasional occurrence, however, does not indicate fraud. 



Chemistry. — Cusso contains a bitter resin, a trace of 

 volatile oil, 24 per cent, of tannin, traces of valerianic 

 and acetic acids, and koussine, which Liechsenring 

 claims to consist of protokosine and koussotoxine, the 

 former crystalline and inactive, the latter amorphous, 

 yellow, fusing at 80°, soluble in alcohol, ether, and chloro- 

 form, insoluble in water. Whether koussotoxine or the 

 bitter resin is the active principle is not yet finally deter- 

 mined. 



