SARSAPARILLA. 93 



according to the variety of sarsaparilla and the type of 

 soil in which the root grew. The cortical cells are more 

 or less spherical, and contain, in some varieties, numerous 

 starch grains and crystals ; in others the starch grains are 

 fewer. The width of the entire cortical layer as com- 

 pared with the central cylinder is of importance in the 

 diagnosis of the variety. 



The cortical layer is separated from the central cylinder 

 by a layer of thick- walled cells, the endodermis sheath, the 

 contour of the cells of which is of much importance. 



Inside of the endodermis sheath there is a layer of thin- 

 walled cells, and within this is a cylinder of vessel bundles 

 arranged in a radial manner. The major portion of this 

 cylinder of the vessel bundles is made up of the elements 

 of the xylem, which completely inclose the phloem 

 elements, almost hiding them from sight. 



The xylem contains vessels and fibres. The vessels 

 are from 30 to 40 in number and are of the pitted type, 

 the pores being both simple and bordered, and many of 

 the smaller peripheral vessels have spiral markings. 

 The fibres are very numerous and thick- walled ; their 

 characters are manifest in the powder. 



The phloem consists of small groups of sieve tubes and 

 parenchymatic cells, immersed in the elements of the 

 xylem. These sieve tubes vary widely, those at the 

 periphery being small-lumened ; the inner ones are larger, 

 and the sieve plates are exceedingly oblique. Inside of 

 the cylinder of vessels there is a pith which contains 

 elliptical to spherical cells, rich or poor in starch grains. 

 The starch grains are apt to be compound grains of from 

 2 to 6 granules. 



In attempting to separate the different varieties of 

 sarsaparilla the following points are to be borne in mind : 

 Comparative width of the cortical and central portions; 

 shape and number of rows of cells of the hypodcrmis; 

 shape and size of the endodermis sheath; variation of 



