T. Holm — Anemiopsis Californica. 77 



prominently in works upon general anatomy. Not less than 

 four types of stem-structure are described by Dr. Solereder 

 (1. c), and characteristic of the tribe Saurureaz, to which our 

 genus belongs, is one normal ring of collateral mestome-bun- 

 ales. In regard to the leaf -structure the stomata are said to be 

 confined to the lower surface; in Anemiopsis, however, we 

 observed these to be present also on the upper, and even more 

 numerous. Most peculiar is the development of a hypoderm, 

 so very prominent in Peperomia, besides the hyclathodes. 

 Secreting cells abound in the leaves and stems of both Piperece 

 and Saururece, while secreting ducts are only known from 

 some species of Piper. Very little seems, however, to be 

 known about Anemiopsis, thus we take the opportunity to 

 describe herewith the structure of the various organs in detail. 



The leaf-blade. 



The cuticle of both surfaces is quite thick and prominently 

 wrinkled, which is especially distinct when we examine the 

 epidermis from above (fig. 1). Epidermis consists of relatively 

 small cells with the outer wall moderately thickened except in 

 the secreting cells (SC in fig. 2). For, as may be seen from 

 this figure, secreting cells occur, also, in the epidermis ; they 

 are thin-walled throughout, much larger than the ordinary epi- 

 dermis-cells and sunk below the level of these, thus forming 

 round depressions in the leaf-surface. Long hairs abound on 

 the lower surface and consist of from eight to twelve cells in 

 one row with the cuticle thin and smooth. As stated above, 

 we observed stomata on both surfaces, and they appeared even 

 to be most numerous on the upper ; they have no specialized 

 subsidiary cells, but are surrounded by a somewhat indefinite 

 number of ordinary epidermis cells, from four to six, as may 

 be seen from our Hg. 3 ; viewed in transverse sections, the 

 stomata are level with epidermis (fig. 4). A hypoderm of one 

 layer of cells {H in fig. 2) is developed on both faces of the 

 blade, but of different structure ; the cells are very large and 

 cone-shaped on the upper face with the point towards the pali- 

 sade-tissue ; on the lower face the hypodermal cells are rela- 

 tively smaller and of a roundish outline (fig. 2). 



The leaf is dorsiventral and possesses a distinct palisade- 

 tissue of several layers on the upper face, interrupted here and 

 there by secreting cells ; the palisades are rich in chlorophyll 

 and surround the conical, hypodermal cells, but without reach- 

 ing the epidermis. A pneumatic tissue of irregular, oblong 

 cells, with wide intercellular spaces, occupies the dorsal part of 

 the blade. The mestome-bundles, except the mediane, are 

 small and completely imbedded in the mesophyll ; they are 

 surrounded by a colorless parenchyma-sheath. The midrib is 



