236 M. J. Miinter on the Structure of Nupliar lutea. 



der Hoeven ; but a comparison of the two figures will at once 

 show the difference, P. Payeni being much smaller and not having 

 the posterior wings dentate, and also wanting the broad deep 

 brown band below. 



[To be continued.] 



XXVII. — On the Surface of the Stem and Contents of the Medul- 

 lary Cells o/Nuphar lutea {Smith). By Julius Munter*. 



Although the internal structure of the submersed stems of 

 Nuphar lutea, Sm., is but little adapted for indicating the dico- 

 tyledonous nature of the Nymphceacea, 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 2^ 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 

 Cycadecs, 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 foveolse 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 foveolse 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 foveoles, 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 ring running parallel with the limb, i. e, con- 



* Translated from the Botanische Zeitung, Aug. 1845. 



