EUCALYPTUS 465 



oidal oil-secretion cavities with a yellow or orange oily content ; near 

 the middle of the leaf is a small layer of loose mesophyll in which are 

 secreted crystals of calcium oxalate in the form of rosette aggregates 

 or rhombohedra, from 0.015 to 0.25 mm. in diameter; the epidermal 

 cells on the dorsal surface resemble those on the ventral surface, but 

 the stomata are more numerous; the fibrovascular bundles of the 

 petiole and midrib have a more or less interrupted circle of slightly 

 lignified bast fibers. 



Powder. Light green; calcium oxalate in rosette aggregates 

 or monoclinic prisms, from 0.015 to 0.025 mm. in diameter; frag- 

 ments showing large yellowish- or orange-colored oil secretion cavities 

 and numerous palisade layers; outer walls of epidermal cells about 

 0.020 mm. in thickness. In leaves from younger parts of the tree, 

 the outer walls of the epidermal cells from 0.005 to 0.008 mm. in thick- 

 ness, the palisade tissue is developed beneath the ventral surface 

 only, while the stomata are present only on the dorsal epidermal 

 layer. 



Constituents. Volatile oil 3 to 6 per cent, of which over 60 per 

 cent is eucalyptol (cineol), the remainder consisting of d-pinene 

 (eucalypten) and other \erpenes; several resins, one of which is 

 crystalline and colored brownish-red with ferric chloride; a neutral 

 bitter principle; eucalyptic acid; tannic acid and calcium oxalate. 



Allied Plants. The following Eucalpyts yield an oil consisting 

 principally of eucalyptol and pinene, and in which the eucalyptol 

 exceeds 40 per cent, phellandrene being absent: Eucalyptus resini- 

 fera, E. polyanthema, E. Behriana, E. Rossii, E. pendula, E. dealbata, 

 E. tereticornis linearis, E. rostrata borealis, E. maculosa, E. camphora, 

 E. punctata, E. squamosa, E. Bridgesiana, E. goniocalyx, E. bicolor, 

 E. viminalis, E. populifolia, E. longifolia, E. Maideni, E. Globulus, 

 E. pulverulenta, E. cinerea, E. Stuartiana, E. Stuartiana var. cor- 

 data, E. Morrisii, E. Smithii and E. sideroxylon. 



Literature. Baker and Smith, A Research on the Eucalypts; 

 McClatchie, the Eucalypts Cultivated in the United States, Bull. 

 No. 35, Bureau of Forestry of the U. S. Department of Agricul- 

 ture; Kraemer, Amer. Jour. Pharm., 1904, p. 177. 



Eucalyptus Kino. AUSTRALIAN KINO, RED GUM OR EUCALYPTUS 

 GUM. The inspissated juice of Eucalyptus rostrata and other species 

 of Eucalyptus. It occurs in masses or small fragments, which are 

 of a ruby or garnet-red color (not reddish-black), somewhat dusty, 

 but not so brittle as Malabar kino. It contains 40 to 50 per cent of 

 tannic acid; kino red, and catechin. About 80 to 90 per cent is 

 soluble in cold water, the solution having a neutral reaction. Austral- 



