Onar: XVIII] STRUCTURE OF THE BLADDERS. 549 
green shoots. They penetrate the earth sometimes to the 
depth of more than 2 inches: but when the plant grows as 
an epiphyte, they must creep amidst the mosses. roots, 
decayed bark, &c., with which 
the trees of these countries are 
thickly covered. 
As the bladders are attached 
to the rhizomes, they are neces- 
sarily subterranean. They are 
produced in extraordinary num- 
bers. One of my plants, though 
young, must have borne several 
hundreds; for a single branch 
out of an entangled mass had 
thirty-two, and another branch, 
about 2 inches in length (but, 
with its end and one side 
branch broken off), had seventy- 
three bladders.* The bladders 
are compressed and rounded, with 
the ventral surface, or that be- 
tween the summit of the long 
delicate footstalk and valve, ex- 
tremely short (fig. 27). They 
are colourless and almost as transparent as glass, so that they 
appear smaller than they really are, the largest being under 
the s> of an inch (1°27 mm.) in its longer diameter. They 
are formed of rather large angular cells, at the junctions of 
which oblong papille project, corresponding with those on 
the surfaces of the bladders of the previous species. Similar 
papille abound on the rhizomes, and even on the entire leaves, 
but they are rather broader on the latter. Vessels, marked 
with parallel bars instead of by a spiral line, run up the 
footstalks, and just enter the bases of the bladders; but they 
Frc. 26. 
(Utricularia montana.) 
Rhizome swollen into a tuber; the 
branches bearing minute bladders; of 
natural size. 
* Prof. Oliver has figured a plant that the bladders on the rhizomes of 
of Utricularia Jamesoniana (‘ Proc. 
Linn. Soc.’ vol. iv. p- 169) having 
entire leaves and rhizomes, like those 
of our present species; but the mar- 
gins of the terminal halves of some 
of the leaves are converted into 
bladders, This fact clearly indicates 
the present and following species are 
modified segments of the leaf; and 
they are thus brought into accordance 
with the bladders attached to the 
divided and floating leaves of the 
aquatic species. 
