558 SCIENTIFIC AND APPLIED PHARMACOGNOSY 



oxalate crystals in monoclinic prisms from 0.010 to 0.045 mm. in 

 length, fragments of leptome associated with yellowish-brown 

 resinous laticiferous cells; tracheae mostly with reticulate thickenings 

 or simple and bordered pores and associated with short wood fibers 

 having prominent oblique pores; stone cells of variable shape and 

 varying from 0.040 to 0.110 mm. in length, the walls being from 

 0.006 to 0.012 mm. in thickness, slightly lignified and traversed with 

 prominent often branching pores; lignified cork cells relatively few. 



Constituents. The root contains from 4 to 13 per cent of resin, 

 which is of an exceedingly complex nature, consisting to a large 

 extent of the glucosides and methyl pentosides of jalapinolic acid 

 and its methyl ester. Also from 20 to 33 per cent of dextrose; 2.5 

 per cent of saccharose; tannic acid; and gum. 



Scammoniae Mexicana Radix. The root of Mexican Scammony, 

 Ipomoaa orizabensis, a perennial, twining shrub indigenous to Mexico, 

 is also often seen on the market and on account of the high resin 

 content, the latter is to some extent sold for or admixed with that 

 obtained from Levant Scammony. It is not infrequent to find the 

 two drugs confused, that is, the one under the label of the other. 



Mexican Scammony usually occurs in nearly flattened, trans- 

 verse segments, varying from 2 to 12 cm. in diameter and from 

 1 to 5.5 cm. in tkickness; externally light to dark brown, very 

 deeply wrinkled, fragments showing the crown frequently have 

 portions of the cylindrical rhizome attached, having large circular 

 stem scars; fragments of the lower portion of the roots having numer- 

 ous short, cylindrical, somewhat spirally twisted root branches; 

 fracture tough, fibrous; inner surface light brown; characterized by 

 alternating zones of collateral fibrovascular bundles formed by 

 successive cambiums, separated by broad strands of parenchyma and 

 brown resinous laticiferous cells; odor distinct, somewhat aromatic 

 and resembling jalap. 



The inner structure of Mexican scammony is as follows: A thin 

 outer corky layer consisting of several rows of brownish, thin-walled, 

 narrow tabular cells; phelloderm of several layers of colorless, thin- 

 walled cells; a broad cortical layer made up of thick-walled, tangen- 

 tially elongated cells, containing either starch grains or crystals of 

 calcium oxalate and numerous large brownish resinous laticiferous 

 cells, containing not infrequently a yellowish-brown, amorphous 

 content; alternate rings or zones of collateral fibrovascular bundles 

 separated by broad medullary rays; fibrovascular bundles consisting 

 of wide tracheae marked by simple pores, and associated with numer- 

 ous, relatively thick-walled wood fibers, having bordered pores; 



