PLYMOUTH MATUNE BIOLOGICAL LABORATORY. 67 



fails to extract it. The violet colouring matter could not be extracted 

 by glycerin, and no haBmatoporpbyrin could be obtained by extract- 

 ing the integument with alcohol and sulphuric acid, whereas in 

 Uraster ruhens, especially in brownish specimens, that pigment is 

 present as I have shown.* Nor was any found in Goniaster, 

 Solaster, Asterina, nor in Holothuria nigra and Ocnns hrunneus. The 

 integuments of the first three yield lipochromes, which are described 

 in the full paper. Holothuria nigra contains within it, and colouring 

 its ovaries, its blood, its digestive gland, &c., one or more lipo- 

 chromes. The polian vesicle contains what may be described as a 

 lipochromogen, and in the blue ovaries of Ocnus hrunneus a similar 

 substance is found which, under the influence of alcohol, ether, &c., 

 as in the case of the beautiful blue pigment of the larval lobster and 

 the '' cyano- crystals " of other Crustaceans, becomes changed into 

 a reddish lipochrome. Enterochlorophyllf is present in Goniaster, 

 Solaster, and Asterina, and in these, as well as in many other 

 Echinoderms, notably in Holothuria nigra, there is reason for 

 supposing that its yellow or red lipochrome-constituent is built up 

 in the digestive gland, from whence it is carried to the integument. 

 In the last-mentioned species it is present in the blood. It may be 

 remembered that Dr. Halliburton J has detected a lipochrome in the 

 blood of various Crustaceans, in which also it is prepared in the 

 " liver." So that we may consider the digestive gland of these 

 animals not only an organ in which digestive ferments are prepared, 

 but also as discharging a chromatogenic function. In Holothuria 

 nigra a yellow pigment can be extracted from the integument by 

 alcohol, which possesses a magnificent emerald-green fluorescence. 

 This has been described by Krukenberg§ as a " Uranidine,'^ and it 

 has also been described by Prof. Jeffrey BelLy To the latter I am 

 indebted for a solution of the colouring matter which I have de- 

 scribed in full in the paper referred to. 



Coelenterata. — The discovery of polyperythrin (which I have 

 shown to be identical with hsematoporphyrin) in many Coelenterates 

 by Prof. Moseleyl,^ led me to hope that in the brown pigment of 

 Chrysaora I might see a banded spectrum, but I could not see any 

 bands whatever, and my further results have confirmed exactly 

 those of Prof. McKendrick,** who examined this jelly-fish. 



In the beautiful little Corynactis viridis, when it has a red colour, 



* Jl. Physiol., vol. vii. No. 3; see also vol. viii. No. 6. 



t See Proc. Roy. Soc, vol. xxxv (1883), p. 370, et seq. ; also Philos. Trans., Pt. i, 1886. 



J Jl. Physiol., vol. vi. No. 6. 



§ Vergl. physiol. Stud., II Keihe, 3 Abth., 1882, S. 53. 



II Proc. Zool. Soc, Dec, 1884, p. 563. 

 1[ Quart. Journ. Mic Sci., vol. xvii, N.S., 1877. 

 ** Journ. Anat. and Physiol., vol. xv. 



