CARTER, ON THE COLOURING MATTER OF THE RED SEA. 181] 
sighted in the lower part of the Red Sea after leaving Aden, 
it again appeared, and we frequently passed through large 
areas of it, sometimes continuously for many miles, until we 
arrived off Jubal or the last island in the upper part of the 
Red Sea, when, from a calm, we steamed into a strong 
northerly breeze, accompanied by heavy sea, and saw no more 
of it. Once ouly I saw a portion of brilliant red and one of 
intense green together in the midst of the yellow. 
The odour which came from this scum was like that of 
putrid chlorophyll, well known to those who have had much 
to do with the filamentous Algze, both marine and fresh-water, 
but more familiarly to those who have not had this experi- 
ence by that which comes from water in which green vege- 
tables have been boiled—and hence very disagreeable. 
I drew up some of this scum in a bottle, and found it to 
be composed of little, short-cut bundles of filaments, like 
Oscillatoria; for I had only a Coddington lens with me for 
their observation; and on showing them to Mr. Latimer 
Clark, the well-known superintendent for laying down the 
telegraph-cable through the Red Sea, &c., to Kurrachee, who 
was on board, Mr. Clark said that he had observed the 
same phenomenon in the Sea of Oman, where he had ex- 
amined the filaments of the little bundles with a microscope, 
and had found them to be “ beaded,”’ to use his expression, 
“ with rounded extremities.” 
On arriving in England, I had no time for examining 
microscopically the specimens which I had cbtained, and 
which had been preserved in an equal quantity of alcohol 
added to the sea-water in which they had been taken, till 
January (1863), when i found the little bundles, which were 
still just visible to the unassisted eye, and like so much fine 
“sawdust” (to which they have been aptly and commonly. 
compared by previous observers, who have seen them without 
knowing what they really were), varying in point of measure- 
ment, although, on the average, perhaps about 3, inch long 
90 
by +1 broad, containing about twenty-five to sixty filaments, 
100 
each of which is about =), inch long by +, broad, their 
cells, which, of course, are so many discs, being sometimes 
thinner, sometimes thicker, than the breadth of the filament, 
with rounded cells terminately at the extremities where entire, 
but square when the latter have been broken off from the 
filament. The bundles bore no evidence of an investing 
sheath, but of the filaments being held together by mucus 
secreted from them generally. 
Further into this description I need not enter, except to 
state that the cell was a true Oscillatorial one, charged with 
