THE MICROSCOPE. 



Vol. V. ANN ARBOR, AUGUST, 1885. No. 8. 



ORIGINAL COMMUNICATIONS. 



THE MICROSCOPIC STRUCTURE OF COPTIS TRIFOLIA. 



LOUISA REED STOWELL. 



GOLDTHREAD was such an important American drug at one 

 time that Dr. Bigelow said : " Of this article larger quan- 

 tities are sold in the druggists' shop in Boston than of almost any 

 other indigenous production." 



It appears now to be principally employed for domestic use 

 for sore mouths, hence called Mouth-root and Canker-root. It 

 is extensively used in domestic medicine in France as an ap- 

 petizer and general tonic. The slender, wiry, bright yellow 

 rhizomes give it its appropriate name of Gold-thread. The mi- 

 croscopic structure of its various parts is both interesting and 

 beautiful. 



Rhizome. — On the outside of the rhizome is a row of epi- 

 dermal like cells, having a thick, clear, white wall, thickened 

 on the outer surface, thus resembling the cuticle. Occasionally 

 it surrounds the entire cell. The most of these cells are empty, 

 though a few of them are colored a bright yellow. These cells 

 are quite uniform in size and shape. On a cross section they are 

 round or square, but on the longitudinal section they resemble 

 the cells of the epidermis of the leaf over the midrib or promin- 

 ent veins. They are long and narrow, and the walls are not of 

 uniform thickness, but covered with irregularly placed nodules. 



The outer two or three rows of cells of the parenchyma are 

 smaller, with walls considerably more thickened, than the rest. 

 The walls are a clear white, even glistening like collenchyma. 

 They are frequently empty, sometimes containing a few starch- 



