Note 1457 — I.—PHÆNOGAMOUS OR FLOWERING PLANTS. (continued 12)
Reading edition
Beautifully delineated by Hanstein in the work referred to at p. 352, note 2; see also Trécul, Ann. des Sciences nat. Bot. v. (1866) 69; Dippel, Entstehung der Milchsaftgefässe, Rotterdam, 1865. tab. 1. fig. 17.