226 THE UNIVERSITY SCIENCE BULLETIN. 



Sections of leaves were treated with methylene blue as a mucil- 

 age test. The inner cell wall of some of the epidermal cells took 

 the stain (figs. 1, 26). 



Sections of the leaf heated in Millon 's reagent showed brick-red 

 contents in the palisade and spongy parenchym^a cells. 



Sections treated with fresh ferric chloride solution gave no tan- 

 nin reaction. 



Compound crystals of calcium oxalate were demonstrated by 

 the use of hydrochloric acid, in which the crystals disappeared 

 without effervescence. These crystals were common in the border 

 parenchyma of the large veins. 



Stem. 



Sections of older stems treated with iodine showed the presence 

 of much starch in the outer cells of the pith and also in the medul- 

 lary rays. 



Fehling 's solution used on sections of the stem showed cuprous 

 oxide crystals, and these increased in number and size when sec- 

 tions were left in a incubator for several hours, thus indicating 

 the possible presence of saccharose and glucosides in addition to 

 glucose. 



Young stems showed the presence of oil in elaioplasts, but in 

 older portions of the stem the sections gave no oil reactions. The 

 glandular hairs of the stem and the petiole have drops of oil col- 

 lected at their apices. Sudan III stains these drops, collected on 

 a slide, a bright red. When left on a slide on a 50° oven for twenty- 

 four hours the oil did not disappear. It is thus probably fatty oil. 



Protein tests were made with Millon 's reagent, chloroiodide of 

 zinc, and iodine, showing protein present only in the region of the 

 phloem and cambium. Methylene blue showed mucilage present 

 in the pith and a very little in the cells of the cortex, and when 

 fresh sections of the stem were placed on the slide and water ap- 

 phed to them, swelling and finally solution occurred in the second- 

 ary thickenings of the walls of some of the pith cells. 



Calcium oxalate crystals are present in cells of the cortex and 

 young pith. 



Sections treated with ferric chloride gave no evidence of tannin. 



Sections treated with saturated copper acetate solution for three 

 weeks failed to show the presence of resin. 



Alkaloid tests were made with potassium iodide and chloro- 

 iodide of zinc. Other sections soaked in alcoholic tartaric acid, a 

 solvent of alkaloids, were compared with fresh sections. No brown 

 precipitate was demonstrated, leading to the inference that no 

 alkaloids were present. 



