CHAP. I. 
CELLULAR TISSUE. 
13 
constitutes the lining of the valves of almost all anthers. The 
forms under which it exists in these parts are far more various 
than those of membranous cellular tissue. The principal 
varieties are these : — 
A. Membrane and Fibre combined, 
1 . Fibres twisted spirally, adhering to a spheroidal or angu- 
lar membrane, and often anastomosing irregularly, without the 
spires touching each other. (Plate I. fig. 12.) This is what 
is found in Oncidium altissimum leaves, in the aerial roots of 
some Orchideous plants, in the lining of many anthers, and is 
what Mohl has figured ( Ueber die Poren, Sfc. tab. i. fig. 9.), 
from the pith of Rubus odoratus. It approaches very nearly 
to the nature of spiral vessels, hereafter to be described, and 
appears only to be distinguishable by the spires of the fibres 
not being in contact, being incapable of unrolling, having no 
elasticity or tenacity; and by the bladders not being cylindri - 
cal and tapering to each end, but spheroidal. 
2. Fibres crossing each other spirally, and forming a reti- 
culated appearance by their anastomosing within oblong blad- 
ders. Of this nature are the reticulated cells of the seed-coat 
of Maurandya Barclayana, Wightia gigantea, and the like. 
(Plate I. fig. 11.) 
3. Fibres running spirally close together, except at certain 
places where they separate and leave between them small 
spaces, which appear like dots. 
4. Fibres running spirally, but completely grown together 
except at certain spaces where they separate and leave small 
dot-like spaces. This and the last have been noticed by Mr. 
Valentine in Orchideous plants, and have been extremely 
well figured by Slack. {Trans. Soc. Arts, vol. xlix. t 6, 
/ 5, 6.) 
5. Fibres running straight along the sides o truncated 
cylindrical cells in the anthers of Calla aethiopica and many 
other plants. (Plate 1. fig. 13.) 
6. Fibres running transversely in parallel lines round three 
of the sides of prismatical right-angled cells, in the anthers 
of Nymphaeaceae, &c. 
