820 ON NAIAS GRAMINEA DEL., VAR. DELILEI MAGNUS. 
fig. 23; a vertical section of N. minor in = 27; 
and a vertical section of N. major. in fig. 2 
h rane which invests the ee is 
formed of close-ranked, elongate, translucent 
position of this rosy membrane over the lemon- 
coloured pollen of the anther gives the flower a 
tawny-orange appearance, bint readily attracts 
notice, even aereboiit the aid of alens. The cells 
which compose the ridges in the upper half of 
the flower are larger and broader than those of 
the rest of the membrane. 
obert Brown’s N. tenuifolia has considerable 
affinity with the Manchester plant, but, inde- 
pendent of other differences, the anther is very 
issimilar on account of its external tunic terml- 
instead of its emerging through the summit of 
the beak of the 4 —— it is thrust through a 
rupture in the 
In 7 7 eee ihe external Mit aictne closely 
invests the inner membrane, but it is not pro- 
on ‘ais portion of the male flower 
XII.—Tue Potzen. 
b The pollen of me various species of Naias does not seem to 
ave been much noticed by observers. Magnus does not allude to 
the works of later authors, one of the most recent being given in 
the ‘ Genera plantarum’ of Bentham and Hooker, vol. iii p. 1018, 
viz., *‘ pollen g globosum.” In the ‘ Compendio della Fork ‘tatiana’ 
of Cesati, Passerini, and Gibelli, part 1, p. 204, tab. XXVil., ote 
the pollen of N. major is elliptico-cylindrical like a grain in of ri 
