ABSTRACT
In view of the relations which are believed to exist between the vitamin content of the diet and that of the fats stored in an animal’s body it is of considerable interest to examine the oils separated from phytoplankton and zooplankton respectively. The isolation of the oils and the results of their general chemical examination are described in a preceding paper (Collin, 1934).
A fuller account of the processes of extraction of the oils from the plankton will be found in Part II, “General character of the plankton oils,” Collin, G., Drummond, J. C., Hilditch, T. P. and Gunther, E. R. (1934).
Later examination of oily material isolated from phytoplankton has confirmed our view that both carotene and xanthophyll are present in the green surface species. Vitamin A as such is apparently absent. The parallel with land-plants is, therefore, very close.
We are indebted to Dr R. A. Morton of Liverpool University for making this spectroscopic test.
Unpublished data.
A pigment showing the same absorption bands has been detected by Lönnberg (Ark. f. Zool. 1932, 25 A, No. 2) in a number of fish. The maxima are at 4520 − 4510 and 4820 − 4810 A
