186 Kansas Academy of Science. 



been made in microscopical botany. Descriptions of crude drugs 

 requiring the use of the compound microscope are found repeatedly 

 in the text. Scattered here and there in the text of the pharma- 

 copoeia are found such statements as the following, quoting a para- 

 graph under Althaea ( marshmallow) : "The powder contains 

 rosette-shaped crystals of calcium oxalate, about 0.025 mm. in di- 

 ameter, and ellipsoidal starch grains from 0.010 to 0.020 mm. in 

 diameter." 



The measurement of the official ( corn ) starch is stated as from 

 about 0.010 to 0.025 mm. in diameter, but these are usually polyg- 

 onal grains. In elm bark there are noted a few nearly spherical 

 starch grains measuring from 0.005 to 0.010 mm. in diameter. We 

 frequently hear the statement made that lycopodium consists of 

 the pollen of Lycopodium clavatum. The pharmacopoeia states 

 that these microscopical elements are tetrahedral spores, from 0.025 

 to 0.040 mm. in diameter, and are multicellular; and that the mi- 

 croscope should reveal neither pollen nor starch grains. 



In the case of Sinapis (both black and white mustard seed) and 

 in flaxseed, the presence of starch, while admitted, is not revealed' 

 by the microscope. In these cases a "limit test" for starch is given, 

 which, in the case of the mustards, reads as follows: "If 1 gm. of 

 the powder be exhausted by slow percolation with alcohol and the 

 mass mixed with 200 c.c. of water and heated to boiling, and if, 

 after cooling, sufficient cold water be added to make the mixture 

 measure 1000 c.c, the addition of 4 c.c. of tenth-normal iodine t. s. 

 should not produce a dark blue color." 



In the case of flaxseed, the limit test is substantially the same, 

 but varies from the former, as will be seen: "If 1 gm. of ground 

 linseed be mixed with 20 c.c. of water and the mixture heated to 

 boiling, then cooled and diluted with cold water to 100 c.c, the 

 addition of 0.5 c.c. of iodine t. s. should not produce more than a 

 pale blue color." 



It is important to note in this connection also that the compound 

 microscope is called into requisition in the identification of anatomical 

 structures, as, for example, in the description of the barks derived 

 from Viburnum opulus and Viburnum prunifolium. Under V. op- 

 ulus it is stated that transverse sections of the bark show several 

 bands of bast fibers ; while in the case of the prunifolium the 

 statement is met that the cross-sections show groups of stone cells. 

 These elements are satisfactorily distinguishable only by the aid of 

 a one-inch (better by a one-fifth) objective, and seem to distinguish 

 the two barks, even in form of powder. 



