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



sequence of the fissiparation is the constant shedding- of their 

 capsules, which are always present with them in great numbers, 

 and so brittle that pressure of the thinnest piece of glass bursts 

 them, and again sets free the Peridinium when they contain one : 

 iodine in dilute sulphuric acid gives them a deep violet colour, 

 and the red matter of the Peridinium is also frequently rendered 

 deep blue by the same solution. 



Thus we see that the red colour is produced by the formation 

 of oil reddened at the expense of the green chlorophyll. The 

 same process takes place in the little Protococcus which I have 

 heretofore shown to impart the red colour to the salt in the salt- 

 pans of Bombay ; and, again, in a freshwater animalcule closely 

 allied to Peridinium, viz. Euglena viridis (probably Ehrenberg's 

 E. sanguinea is but a reddened state of the latter) ; while a more 

 familiar illustration than any is presented to us by the red colour 

 which the leaves of some trees assume towards death, viz. the 

 passing of the green chlorophyll and oil into a yellow, brown, 

 and then red waxy substance ; from whence we may also infer, 

 that like changes in the Peridinium give rise to the prevalence 

 of one or other of these tints in the coloration of the sea. 



The species of Peridinium now more particularly under our 

 consideration I desci'ibed several years since in its fixed form (as 

 it was submitted to me) undergoing fissiparation*; but never 

 having met with it again in its active state until the 26th Nov. 

 last, mjr attention was not again drawn to the subject, nor did 

 I until then know what the animalcule really was. I shall call 

 it animalcule, though, like Euylena and all this class, it really 

 belongs much nioi'e to the vegetable than the animal kingdom ; 

 and, believing the species to have been hitherto unrecognized, 

 its description, under the designation oi sanguineum, may stand 

 as follows : — 



Peridinium sanguineum, nov. sp. 



Subcircular when green, becoming larger and paraboloidal or 

 kite-shaped when red. Compressed, sulcated on one side ; 

 surrounded transversely by a deep groove, the anterior lip of 

 which is minutely ciliated. Furnished with a long, large 

 cilium, having a suctorial extremity, which extends backward 

 from the groove on the sulcated side. Body lined with gra- 

 nular protoplasm and chlorophyll, in which is a hyaline vesicle 

 with a red eye-spot and a nucleus as in Euglena. Chlorophyll 

 becoming of a golden yellow, then brownish, and lastly ver- 

 milion- or minium-red, as the animalcule passes into the Proto- 

 coccus-state. Progression waddling, the small end forwards, 



* Dr. Buist, "On Discolorations of the Sea," &c., Proceedings of the 

 Bombay Geographical Society, 1855, p. 109. 



