16 NATURAL HISTORY OF PLANTS. 



But the transition is now still more gradual since tlie discovery in 

 Angola of the Campylostemon, a climbing shrub with opposite leaves, 

 and possessing, it is said, pentamerous flowers, five alternipetalous 

 stamens, with introrse and transverse dehiscence. 



VI. BOX SEEIES. 



The Boxes ^ (fig. 28- 34), long referred to the family of the 

 Euphorhiacece, have regular and unisexual apetalous flowers. The 

 calyx of the male flower is formed of four sepals, alternately imbri- 

 cated in prefloration. Superposed to them are four stamens, each 

 formed of a thick filament, long and free, inserted under the four 

 faces of a central cuboid body (rudimentary gynsecium?) whose 

 angles project more or less into the intervals, and a bilocular introrse 

 anther dehiscing by two longitudinal clefts.^ In the female flowers, 

 the perianth is more ordinarily formed of six imbricate folioles, 

 alternating on two trimerous verticils and surrounding a gynsecium, 

 the ovary of which has three cells, each enclosing two ovules, 

 inserted near the top of the internal angle, descending, anatropous, 

 with raphe primarily dorsal and micropyle directed upwards and 

 inwards. The summit of the ovary is generally surmounted by six 

 projections. Three of these, slightly developed, correspond to the 

 partitions, and the three others, more considerable, corresponding to 

 the cells, are stylary branches, of eccentric insertion,* which diverge 

 and separate at the summit into two short lobes. The internal 

 margin of these styles is traversed by a longitudinal furrow, the 

 reflexed lips of which are covered with stigmatiferous papillae. The 

 fruit is a tricoccous and loculicidal capsule which at maturity separates 



1 Buxus T. Inst. 578, t. 345.— L. Oen. n. Aeg. Pto*??-. xvi. p. 1, M.— Tricera&u. Prodr.i. 



1063.— Adams. Fam. des PI. ii. 365.— J. Gen. 333, t. 7.— Endl. Gen. n. 5%&%.—CrmUia Sw. 



388. — GiEETN. Frmt. Ti. 125, t. 108.— Lamk. -Prai^?"- 38 (not Lao. norNuTT. nor Schreb. nor 



ma. i. 510; Suppl. i. 742; III. t. 761.— A. Scop.). 



Juss. Tent. 3uphorhiao. 13, t. 1, fig. 3.— Nees, ^ The pollen grains are spherical with very 



Gen. t. 56. — Spach, Suit. u. Buffon, ii. 491. — fine pores. 



Endl. Qen. n. 5869.— H. Bn. Bull. Soc. Bot. de ^ They approach the centre in a species from 



Fr. iii. 285 ; Monogr. des Buxac. et dea Styloc6r. the Antilles, B. sulcolumnaris M. arq. 

 (1869), 2, 68, t. 1, 2 ; Adansonia, xi. 283. — M. 



