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THE JOURNAL OF PHARMACOLOGY. 



Microscopically the following elements enter more or less conspicuously 

 into the powder : Starch, crystals, cork, parenchyma, wood fibers, trache- 

 ids and vessels. 



The starch is the most characteristic feature of the powder and is al- 

 most of diagnostic value alone. The grains are simple, and in twos, 

 threes and occasionally in fours. The hilum is centric, the margins 

 rounded. In many cases compound granules are observable ; in these 

 compound granules the size of the different granules varies, a point which, 

 according to Tschirch, is of importance. The average diameter of the 

 starch grains is from 7 to 9 micra ; some of the larger granules may 

 measure from 17 to 19 micra. Kamer gives 4 to 7. The smallest are 

 usually about 2 micra. The starch of Carthagena ipecac is said to range 

 on the average larger than that of Rio ipecac. Schneider's figures are 

 from 17 to 23 micra. 



The crystals are of the acicular variety, usually lying in special cells, 

 but in the powder dislodged therefrom, they range in length from about 

 20 to 100 micra, though' this only represents an average. 



The cork cells are dark-brown, and without clearing are usually in- 

 distinct in outline ; in size the cells range from 9x15 to 15x25 micra. 



Powdered Ipecacuanha— S, starch grains ; P, parenchymatic tissue ; Trach, tracheids ; C, crystals ; 

 Fibr, fiber-like tracheids ; Tr, Vessel ; vessel-like tracheid ; St, stone-cells ; Cork : to left, tangentially, 

 to right, from surface ; O, tissue from phloem ; V, spiral vessel from stem. 



