ON NAIAS GRAMINEA DEL., VAR. DELILEI MAGNUS. 829 
_ Chara Braunii axe so often pec together as to give a strong 
colour to the surmise of their common origin. There is nothing in 
the recorded distribution of Chara Braunii to forbid its being 
ultimately shown to be aboriginal, but until it is recorded from 
other British stations, with fewer doubtful surroundings than it 
ne. in the Manchester station, it can only be looked upon as a 
coloni 
XIX. —A Hisrontoeican Pecunsariry. 
A still stronger proof of its Egyptian extraction is furnished 
from the histological s ide. This part of the case has been dealt 
with by Dr. gee in a paper r a to the German Botanical 
Association at Berlin, December 11th, 1883, and 1 make no 
apology for reproducing here the substance of this interesting 
communication. In describing the structure of Naias graminea on 
page 138, I mentioned that there were two forms of the plant; one, 
‘Other, destitute of these bast-cells. This latter form Dr. Magnus 
names the yar. Delilei, and he states that the English specimens 
belong to this variety, and Smagpetied are ther EH 
Source. The f following are some s from the paper of 
Dr. Magnus, published in the T patichn dor deutsch. Botanischen 
Gescllcohal, : y ahrg. 1888, Bandi., Heft 10 :— 
“T have examined the specimens of Na ae graminea collected by 
Delile in eves rice-fields near Rosetta, as also those obtained by 
Schweinfurth near Benha-el- pis in the Nile Delta, ad bave a 
the é without bast-ne They are also wa nting in 
eo collected sf Gaillardet, : near Saida in Syria, which hs 
been indly communicated to me by M. Boissier. I was er 
enable, through the kind communication of Professor Ascherson, 
to examine specimens of Najas graminea Del., collected by him 
Grea 
ce From this it would appent that ti Najas graminea 
Schweinfurth near Chargeh, have all well-developed aia 
similar to the plants of Cordofan, Djur, Algeria, Colebes, & 
“The absence of these bast-nerves in a variety of. ‘Négas 
graminea ig ae more cotiat A as through the eee artiah of the 
al of N. tenuifolia R. Br. [see fig. 15, Plate 251], from 
Australia, wal a differs so materially, i precisely the same bast- 
nerves in exactly the same shaped libriform cells on the leaves ; 
Consequently these bast-nerves represent the distinetive character 
of a group of allied species, but still subject to variations. . ... 
“I have mentioned above that the one set of specimens from 
-Dachl and Chargeh had leaves without bast-nerves, and 
