184 Mr. H. J. Carter on the Colouring Matter of the Red Sea. 



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 only I saw a portion of bril- 

 liant 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 Algge, both marine and freshwater, but more 

 familiarly, to those who have not had this experience, by that 

 which comes from water in which green vegetables 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 

 stated that he had observed the same phenomenon in the Sea 

 of Oman, where he had examined 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 micro- 

 scopically the specimens which I had obtained, and which hud 

 been preserved in an equal quantity of alcohol added to the sea- 

 Water in which they had been taken, till January (18G3), 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 measurement, although, on the average, per- 

 haps about j^ inch long by j-^ ^y broad, containing about twenty- 

 five to sixty filaments, each of which is about j'^ inch long by 

 2TG0 broad, their cells, which of course are so many disks, 

 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 invest- 

 ing 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 a few 

 granules suspended in its protoplasm, and that I saw nothing 

 like sporidification. 



The colour of the bundles to the unassisted eye was still faint 



