236 M.J. Minter on the Structure of Nuphar lutea. 
der Hoeven ; but a comparison of the two figures will at once 
show the difference, P. Payeni beg much smaller and not having 
the posterior wings dentate, and also wanting the broad deep 
brown band below. 
[To be continued. ] 
XX VII.—On the Surface of the Stem and Contents of the Medul- 
lary Cells of Nuphar lutea (Smith). By Jutivs Minrer*. 
AttuoucH the internal structure of the submersed stems of 
Nuphar lutea, Sin., is but little adapted for indicating the dico- 
tyledonous nature of the Nympheacee, still in other respects it 
possesses so much interest, that it appears well-worthy of a spe- 
cial notice in these pages. The stem of the yellow water-lily is 
found in tolerably deep stagnant waters, lakes and large rivers ; 
its length is 5 feet or more, and its diameter from 23 to 3 inches ; 
it is sometimes simple and sometimes branched, and sends off 
from its summit to the surface of the water its floating leaves and 
beautiful flowers on smooth footstalks, which are often 6 to 8 
inches long. The stem is sometimes brought to the surface of 
the water or the banks either by the net of the fisherman or the 
drying up of the water, and we are then enabled to examine it 
more accurately. 
The entire surface of the stem is coated with elastic leaf-scars 
directed obliquely from above downwards, as in the stems of the 
Cycade@, and the torn bundles of woody fibre are indicated on these 
scars. We do not, however, usually find any buds in the angles 
of the leaf-scars, and in such a case not even the slightest trace 
of one. But where the buds situated in the angles are developed, 
they form a branch directed almost at right angles to the axis, 
which soon acquires the thickness of the stem. A little below 
the leaf-stalk scars, which are arranged circularly around the stem, 
we find single or grouped foveolee of the size of a pea, of a more 
or less rounded form, which are either arranged beneath these 
leaf-scars around the stem, or are only visible on those parts of 
its surface directed towards the soil. When these foveole are 
grouped, three, five or six together, the lower ones are usually 
larger than the upper, and on minutely examining them we find 
a remarkable resemblance of each foveole to the cavity of the 
human acetabulum. In the former a circular protuberance 
(limbus) surrounds the fovyeoles, as in the latter, but this has in 
addition a notch at its lower part ; we then find on the inner sur- 
face of the pit a rmg running parallel with the limb, 7. e. con- 
* Translated from the Botanische Zeitung, Aug. 1845, 
