126 PLANT ORGANS OR PARTS OF PLANTS. 



acid. There are also cells filled with ethereal oil in the 

 exoderm. The endoderm is composed of cells which are 

 not very prominent, and extend only a short distance 

 longitudinally. Deep within the endoderm the vascular 

 bundles are more numerous ; they resemble in their course 

 the palm-type of cells, since they penetrate the tissue like 

 leaf -vessel bundles and join with the central bundle. 

 The bundles are concentric and carry the sieve tubes in the 

 inside. In the outermost zone, the collenchymatic zone, 

 there are single short sclerenchymatic fibre bundles. 



Chemistry. — Kurbatow has isolated a sesquiterpene 

 (C15H2J which boiled at 255°. Fliickiger, on the con- 

 trary, isolated an oil of the apparent formula CjoH^gO, 

 which boiled at 255°. The crude calamus oil has a some- 

 what dark-brown color. Such a discoloration may 

 be due to the mixture of a blue oil. Calamus oil 

 furnishes a small amount of such a blue constituent, 

 after the distillation of the principal part of the mixture 

 at 270° to 290°. In addition, it appears to contain a 

 phenol, since the portion which has the highest boiling- 

 point is colored greenish-brown by alcoholic ferric 

 chloride. 



Acornin, CggHg^Oe, is a very bitter, soft glycoside. 

 It was prepared by Thoms by heating the calamus 

 root with water, evaporating the solution after the ad- 

 dition of animal charcoal, and exhausting the residue with 

 boiling alcohol. The product was less than 2 per mille. 

 It is neutral, insoluble in water, soluble in alcohol, 

 chloroform, and ether. Other constituents of calamus 

 are resin, starch, mucilage, calamine, and choline; the 

 latter forms in decomposition, trimethylamin and methyl- 

 alcohol. 



PODOPHYLLUM. 



Podophyllum is the rhizome and roots of Podophyllum 

 peltatum, L., a plant found abundantly in certain locali- 

 ties of the United States. It is very common in north- 



