OLIVE LEAVES 517 



fibrous; taste bitter and astringent. It contains a crystalline glu- 

 coside, fraxin; a crystalline bitter principle, fraxinin; and tannic 

 acid from 2 to 3 per cent. 



Literature. Power, Amer. Jour. Pharm., 1882, p. 99; Edwards, 

 Ibid., p. 282. 



Olea Europaea. The leaves of the olive tree, Olea europsea 

 (Fam. Oleaceae), were employed many years ago as a remedy in 

 intermittent fever, and quite recently attention has again been directed 

 to their therapeutic value as a tonic and febrifuge. Both the leaves 

 and the bark of the olive tree have, therefore, been subjected to a 

 complete chemical examination, which has resulted in the isolation 

 of a large number of new and interesting substances. From olive 

 leaves have been isolated a crystalline substance, oleanol. Power, 

 Jour. Chem. Soc., 1908, pp. 891 and 904; 1913, p. 2050; also Pharm. 

 Jour., 1908, (81), p. 714. 



LOGANIACEJE, OR NUX-VOMICA FAMILY 



A family of about 400 species, which are widely distributed. 

 The plants are variable in character, ranging from annual herbs to 

 trees, some being twining and woody vines. The leaves are simple, 

 the flowers regular, having tubular or somewhat campanulate corollas, 

 and the fruit is either a berry or capsule. According to Solereder 

 they may be divided into 2 principal sub-groups: (1) The Lcganioi- 

 dese, including Gelsemium, Spigelia, Strychnos, etc., in which an 

 intraxylary phloem is always present and glandular hairs are wanting. 

 In this group there is also a superficial development of cork. (2) 

 The Buddleioidese, including a few genera in which glandular hairs 

 are present, the cork originates in the pericycle, and there are no 

 strands of phloem in the pith. Among other histological characters 

 distinguishing this family, the following may be mentioned. The 

 cork is frequently lamellated. There is usually a development of a 

 ring of stone cells in the primary cortex, or outer layers of middle 

 bark, as in certain species of Strychnos. The tracheae possess simple 

 pores, occasionally scalariform perforations, except when the walls 

 are in contact with the cells of the medullary rays, when they develop 

 bordered pores. The walls of the wood fibers have either simple or 

 bordered pores. Calcium oxalate is secreted in a number of forms, 

 viz., ordinary crystals, styloids, rosette aggregates, acicular or micro- 

 crystals. The structure of the leaf may be as follows: The walls of 

 the upper epidermal cells may be metamorphosed to mucilage; a 

 distinct hypodermis may be developed; in the mesophyll there may 



