ON TRAPA NATANS. 239 
Extracts and Abstracts, 
ON TRAPA NATANS, Z., ESPECIALLY THE FORM NOW 
LIVING IN THE SOUTHERNMOST PART OF SWEDEN. 
By F. W. C. Argscnove. 
(Tas. 184.) 
ora in respect to its morphology, its history, and its geographical 
distribution, Zrapa natans, L., is deserving of special attention. The 
h 
morphologist has studied cular the singular capillary 8 
owing from submerged parts of the stems, which organs have 
been considered ome as leaves, corresponding to th -kno 
submerged leaves of many Batrachiums, by others as adventitious 
,. however, to ing truly roots appear 
no en removed b xact inquiries of Reinke 
to e b ery 
('s Sitbeeashica padi tiber Wachathums-geschichte und Morphologie der 
Phanerogamen-Wurzel,” in Hanstein’s Bot. Abhandlungen). 
intercellular system, so greatly pote re in aquatic plants for the 
purpose of keeping their tender and weak stems upright in the water 
or floating on its surface, seems not to be sufficient for the purpose in 
this plant. Its large and ponderous fruits, which appear to have need 
of eth on — surface of the water in order to become ripe, would 
sea. a and increases in proportion as the fruit grows; so that these 
organs attain their full size when the nines is completely grown. The 
larger the fruit the larger are they also; on the forms with small and 
light fruits they are nearly ssoeobentibies: Consequently, this plant 
Ss a new example to the many w > rganic nature exhibits of 
as a nut in almost all the works to which I have had — but 
=a 
is not the outermest covering of the fruit. On the ripe fruit this is 
nd woody 
endocarp at last forms the outermost covering. This circumstance 
has been already noted in the ‘‘ Botanical Register,” iii., 259, though not 
noticed by later Ss the fruit should rather be called a dr rupe 
an urther, it "deserves mention that the spines of the fruit 
to the end of the young plant. These barbs are also foundon the fruit- 
