ON NAIAS GRAMINEA DEL., VAR. DELILEI MAGNUS. 825 
in the stem, but much smaller and more circular (see fig. 89). 
on cavities are regularly arranged in one series ro 
€ central mass, as in the stem, but there are occasionally 
these cells, but on the outermost 
side, are a few cells filled with a 
rich tawny brown 
W. 
a: ae colour of the pigment 
hn addition to the roots proper 
presented in Plate Th 
Fie. 89. are generally given off singly from 
th, between the first pair of leaves of 
€ fascicle ; rarbea e. two proceed from the same node, but in 
such case the econd root enereee on the opposite side of the node. 
the lower eat gae of bg stem the adventitious roots become 
more numerous from each node, and they begin to acquire the 
sae colour of the roots ie gle “They attain a length of from 
Inch to six inches or more, and they have a similar 
intemal Geeaitiers to that of the roots proper; the peripheral cells, 
owever, do not possess the angular character nor the tawny colour 
8 either in shape or in colour, the rich pigment of the corre- 
‘ponding layer in the root being absent. 
XVI.—Tae Lancasume Locauiry, 
The occurrence of a Naias in Lancashire was so unexpected a 
circumstance that I was pleased, through Mr. Whitehead’ 
the Naias grew in an area of about a quarter of a mi 
im Some portions of this space it was the sesaag’ pant wholly 
. with 7, ne canal-bed, while in other portions it was ixed 
wah P ogeton rufescens, P. obtusifolius, P. crispus, P. pusillus, 
