162 



THE JOURNAL OF PHARMACOLOGY. 



from glands which cover the scales. This resin rarely, if ever, is found 

 in quantity on the branchlets, although there is always sufficient secreted 

 by the stem and leaves to impart a glutinous property perceptible to the 

 touch. The resinous secretion changes to a brown color later in the season 

 and covers the heads like a thick varnish. The proper time to gather the 

 plant is when the seeds are perfected." — (Transactions of the Medical 

 Society of the State of California, 1874, pp. 1 16-123.) 



To this might be added that the drug, as it reaches our eastern markets, 

 seldom includes leaves over three inches in length and contains an undue 

 proportion of stems which vary from y 1 ^ to \ inch in diameter, are of a 

 pale yellow or brown color and smooth but for the slight longitudinal 

 wrinkles. The odor of Grindelia is strongly aromatic and quite charac- 

 teristic. The taste is at first aromatic, recalling that of thyme ; later it 

 becomes bitter and lastly persistently acrid, producing at first a stinging 

 and then a numbing sensation on the tongue similar to that produced by 

 a trace of aconite. 



The drug is difficult to powder on account of the tendency of the soft 

 resin to clog up the teeth of the mill, especially when it becomes warm. 



The microscopical characters of 

 Grindelia are numerous. Although 

 the official definition includes only the 

 leaves and flowering tops, the com- 

 mercial drug contains not a little 

 stem, which renders the consideration 

 of that portion of the plant necessary. 

 A cross-section of the stem presents 

 the general appearance of Fig. 1. The 

 center of the section is seen to be com- 

 posed of a pith of delicate thin- walled, 

 large-celled parenchyma. This com- 

 prises about one half of the entire 

 diameter. Surrounding this pith are 

 the fibro-vascular bundles, eight to 

 sixteen in number ; a portion of one of these is shown enlarged in 

 Fig. 2. They are composed of radiating rows of wood cells, with ves- 

 sels and tracheids interspersed, separated by a cambium layer from the 

 dense elliptical masses of bast fibers which produce the slight longitudinal 

 elevations mentioned above. These bast fibers are surrounded by a thin 

 layer of parenchyma enclosed by an epidermis. 



In the larger section this epidermis is seen to be composed of rectan- 

 gular cells somewhat thickened on the outer wall. The layer of par- 

 enchyma immediately beneath (from three to" seven cells in width) is com- 

 posed of thin-walled cells very irregular both in size and shape with the 



Fig. 1. 



