May 1892.] THE BOTANICAL SOCIETY OF EDINBURGH. 435 



Besides them the phh^em contains other elements, viz., 

 cells, sieve-tubes, and fibres. 



The first of these are very numerous, and form, as in 

 D. FranUinii, vertical spindle-shaped groups of from six to 

 nine members which are circular in cross section, except 

 that the radial walls are somewhat flattened where neigh- 

 bouring similar elements come in contact with each other. 

 This flattened area is provided with a single series of large 

 circular or elliptical areas, where no thickening matter has 

 been deposited, otherwise the cell-wall is equally, if but 

 slightly, thickened all over. The wall is lined by a thin 

 layer of tannin -containing substance which has imbedded 

 in it a nucleus, and on its inner side bears numerous 

 mammilliform projections which stand out into the empty 

 interior of the cell. These elements are disposed somewhat 

 irregularly, but in a general way they form separate 

 tangential plates one cell thick, and composed of from two 

 to eight groups of cells applied to each other by their radial 

 walls. Each tangential face is usually in contact with a 

 sieve-tube, which appears in cross section to be more or less 

 meniscus with the concave side next the cell, and the oppo- 

 site convex side applied to one of the tangential walls of a 

 fibre. In this species there are no cells containing only 

 protoplasm, at least in the phloem of an old stem if one 

 excepts those of the medullary rays. 



The sieve-tubes and fibres are similar to those found in 

 D. Franhlinii, but the latter are much less numerous. 



In both species tannin also occurs in considerable amount 

 in ordinary parenchyma-cells of the pith and cortex, but not 

 in all of them. Dacrydium cupressinum has, moreover, a 

 number of tannin-sacs in the xylem-cylinder. These are 

 thin-walled elements which dil^er from the surrounding 

 tracheids only by the absence of thickening layers on the 

 walls and the presence of contents. 



The substance which I have so far alluded to merely as 

 tannin probably contains several other ingredients. As it 

 exudes from a cut surface of I), cuijrcssimtm, it is a watery 

 liquid of a pale yellow colour, which on drying leaves only 

 a thin varnish-like residue. It is so extremely fluid that, 

 as soon as a cell containing it is injured in the process of 

 section-cutting, it escapes, leaving the cell quite empty; 



