1901] - MICROSCOPICAL JOURNAL ~~ 291 
tures have more commonly four or even five cell joints 
abutting on them, instead of three. In most of the air- 
passages there may be found two or more very fine fibre 
bundles running down through the plates. Hxcepting 
these, the spaces between the plates are empty in the 
upper part of the leaves. But in the lower and sheathing 
part, the chambers are filled with slender cells branching 
in every direction, like those in the pith of Juncus ef- 
fusus. The term “stellate” as applied to the Juncus cells,* 
and the figures shown in some of the books are far from 
giving a correct idea of the actual form. Sections made 
horizontally, vertically, or obliquely have about the same 
appearance. Hence the cell branches are quaquaversal 
instead of being in one plane, and they are quite irregu- 
lar. This tissue resembles the texture of fine commercial 
sponge as seen under the microscope. It is spongioid. 
The flower-bearing stem of Typha is solid. Fig. 16 gives 
a transverse section of a Typha leaf, of the real size. 
Fig. 17 represents a portion of one of the diaphragms 
magnified 55 times. Fig. 18 shows a longitudinal of 
some upper air-passages of about twice the natural size, 
with fibre bundles running through the chambers. In 
planes further back other fibres would be seen. They 
appear as dots in fig. 16. 
Diaphragms of a fourth type are found in the petioles, 
scapes, and spadix of Peltandra undulata. In this case 
the cell division lines run between the angles of the 
apertures instead of the sides; and so the cells are poly- 
- gonal and not branching. As this plant is pervaded by 
a colorless jelly insoluble in water, slices are somewhat 
difficult to handle. But the slime may be removed by 
soaking three or four hours in weak ammonia water and 
then washing with clear water. 
*In Engler’s new ‘‘Das Pflanzenreich’’ these cells are called 
‘“‘Parenchymstrangen’’ and the diaphragms ‘‘Parenchymrippen,”’ 
neither of which designations is particularly apt. 
