260 THE JOURNAL OF PHARMACOLOGY. 



usually the largest tracheids, measuring from 12 to 35 miera in diameter. 

 (2) Tracheids with bordered pores ; usually smaller and having no end 

 opening. (3) Ersatzfasern, or wood-fiber-like tracheids, with diagonal 

 pores ; these elements are about 15 micra in diameter and about 300 long. 

 True vessels are not found in the root of ipecac, unless the vessel-like 

 tracheids are included under that head ; functionally they certainly are 

 vessels and morphologically approach them closely. If portions of the 

 rhizome are included in the powder of the root, spiral vessels similar to 

 those figured may be found, also typical stone-like parenchymatic cells, 

 also figured. 



Belladonna. 



The powder of belladonna is usually grayish-brown in color. 



The main histological elements found are starch, ducts, tracheids, fibers, 

 and cork. Crystal sand forms an inconspicuous element of the sand. 



The starch grains are numerous, they are both simple and compound, 

 the compound varieties perhaps about as many as the simple forms. The 

 compound granules exist in twos, in threes, occasionally in fours. The 

 average diameter of the simple grains is about 18 micra ; individual grains 

 average from 10 to 30 micra ; the compound granules range from 20 to 40 

 micra in diameter. The hilum is usually centric, naturallysome what ex- 

 centric in the compound granules, is simple or tristellate, the angles of the 

 grain are usually rounded. 



There being several kinds of belladonna root in the market, certain 

 variations from the types here described may be encountered. These ex- 

 press, however, the averages of a large number of examinations. 



The ducts of belladonna root are. manifest ; few spirals are found, and a 

 number of reticulated and pitted forms and varieties with bordered pores ; 

 much range in diameter of these ducts is to be observed. The average of 

 several measurements gave : Spiral ducts, 18 ; reticulated ducts, 25 ; 

 pored ducts, 40 micra. 



The tracheids are typical and prominent ; their average diameter is about 

 30 micra. They frequently are very heavily pitted and pored. The wood 

 fibers are few, and, as a rule, quite slender ; they average 13 micra in 

 diameter. 



Parenchyma filled with starch grains is predominant. The cells vary 

 widely in size ; they are usually oblong cylindrical, generally being from 

 two to three times as long as broad, and in the main measuring 25 to 60 

 micra. 



Masses of corky tissues, dark and light-brown, are scattered copiously 

 throughout the powder. On clearing the structure of the cells, the walls 

 become manifest. Some few tissues probably derived from the phloem 

 may be encountered with the xantho-proteic test. These tissues give the 

 characteristic proteid reaction for the cell contents. They may be recog- 

 nized by their delicate walls and the character of their contents. 



