BAIRD: ANATOMY OF PLAT ANUS. 287 



mucilage test. The palisade cells, certain cells in both the 

 upper and lower epidermis, and from four to six cells beneath 

 each stoma took the stain (figs. 5 and 6) . 



Sections of leaves which had been preserved in formalde- 

 hyde, when boiled in Fehling's solution, showed no cuprous 

 oxide crystals, probably because the sugar had been soaked 

 out of them. The same sections left in Fehling's solution over 

 night showed a great number of crystals of cuprous oxide in 

 masses. Left another night, the masses grew larger. This 

 reaction indicates the probability of glucosides. 



A section of the leaf boiled in Millon's reagent showed red 

 color in the palisade cells and in some of the epidermal cells, 

 indicating the presence of proteid. A section of leaf treated 

 with concentrated nitric acid and dilute ammonia showed 

 orange color for the contents of the palisade cells, some of the 

 epidermal cells and some of the spongy parenchyma. This 

 color reaction indicates proteid. Sections treated with ferric 

 chloride turned very dark in color, especially the palisade cells, 

 indicating that there is much tannin in the leaf . 



The sticky substance between the two outer bud scales is 

 not soluble in warm water; therefore it is not mucilage. It 

 is soluble in alcohol and xylene, which shows that it is resin. 



The Bark. 



Sections treated with iodine showed the presence of much 

 starch and proteid in the parenchyma of the bark. 



Fehling's solution showed the bark to be loaded with sugar. 



Alcannin and Sudan III showed granular particles having 

 the appearance of oil. 



Traces of volatile oil were obtained by distillation. Cold 

 cover glasses were passed back and forth past the mouth of a 

 tube in which small pieces of bark were being heated. The 

 volatile oils passed over with the steam and were condensed 

 on the cover glasses. 



Methylene blue showed the presence of no mucilage. 



Some sections were soaked two days in water. Part of these, 

 boiled at once in Fehling's solution did not show crystals of 

 cuprous oxide. The rest of the sections put into Fehling's 

 solution and left in a warm oven over night were full of crys- 

 tals in the region of the bark, indicating that there is probably 

 much glucoside here. 



