68 JABORANDI.- PILOCARPUS PKNN ATIFOLIUS. 



MICROSCOPICAL STRUCTURE. 



The cuticle is thick and granular, rather than smooth, appar- 

 ently containing something besides cellulose. (See a, fig. 2.) 

 Directly beneath this is a single layer of epidermal cells (b). The 

 palisade cells (c) are longer and more slender than the average, 

 and loaded with yellow chlorophyll and dead protoplasm. The 

 cells of the loosely packed parenchyma are thinner walled and are 

 more scattered than usual. They are nearly empty. Some of the 

 smaller cells contain a pale, pink-colored oil, thin and clear ; while 

 the oil drops, which are found floating around loosely, are of a 



Fig. 2. Cross section of the leaf of Pilocarpns Peunatifolius. Mag- 

 nified 250 diameters. 



bright yellow, but rendered nearly opaque by the presence of a fine 

 black granular substance. The lower epidermis (e) is smaller and 

 more delicate than the upper. A small fragment of one of the 

 veins or a vascular bundle, showing spiral vessels, is seen at f. 

 There are numerous large stellate crystals found all through 

 the structure of the leaf, rather than on either side of the vascular 

 bundle, as is generally the case. Some are found even between the 

 palisade cells and the upper epidermis. The crystals are of calcium 

 oxalate. The minute dots seen on the under surface of the leaf 

 are internal glands or large openings found on the inside of 

 the leaf. They are always found among the loosely packed paren- 

 chyma, and connecting with the outside through a minute opening 

 on the lower surface of the leaf. These contain a dark yellow 



