182 CARTER, ON THE COLOURING MATTER OF THE RED SEA. 
afew granules suspended in its protoplasm, and that I saw 
nothing like sporidification. 
The colour of the bundles to the unassisted eye was still 
faint yellowish; but the filaments, under the microscope, were 
faiutly green. 
Of the questions proposed by Montagne (op. cit., p. 355), 
the second calls for more information on the size of the 
bundles. This has been supplied above, so far as my obser- 
vation extends. 
The third question calls for information respecting the 
presence of Trichodesmium in the Sea of Oman, &c., as 
bearing upon the origin of the name ‘ Erythrean Sea,” 
applied by Herodotus to all the seas washing the shores of 
Arabia. 
I have already stated that I saw the scum in the Gulf of 
Aden, also that Mr. Latimer Clark had seen it in the Sea 
of Oman; and the following extract from the late Dr. Buist’s 
observations on the “Tuminous and Coloured Appearances 
in the Sea” (‘Proceedings of the Bombay Geographical 
Society’, for 1855, p. 120) will show that it exists in the 
upper part of the Indian Ocean. The account from which 
this is taken was communicated to Dr. Bust by Dr. Haines, 
as witnessed on board the “ Maria Somes,” in lat. 21° N. 
and long. 42° E., and it stands thus: 
“In May, 1840, when one third across from Aden to 
Bombay, the aspect of the sea suddenly changed upon us, 
and at once seemed as if oil had been poured upon its sur- 
face. It was still as a mill-pond, and of a brownish, soapy 
hue. The water, on being examined, was full of little fibrils, 
like horsehair cut across, in lengths of the tenth of an inch 
or so. A wine-glassful of it contained hundreds of them. 
. . « . We sailed through them for about five hours; so 
that they probably extended over a surface of 500 miles.” 
The occurrence, then, of Trichodesmium Ehrenbergii in 
the Red Sea, the Gulf of Aden, the Indian Ocean, and the 
Sea of Oman, is so far substantiated ; and as the yellow colour 
in all instances probably passes ito red, we have, apparently, 
the explanation of the whole of these seas having been called 
by the Greeks ‘ Erythrean.”’ I have not, however, heard 
whether it has been seen in the Persian Gulf. 
Further, we learn from M. Dareste’s memoir (op. cit., 
p-. 208) that Jodo de Castro, in July, 1841, when off Cape 
Fartak, which is about the middle of the south-east coast of 
Arabia, found the sea so red that it appeared as if it had béen 
coloured with bullocks’ blood. 
In my own experience of the Sea of Oman and the whole 
