1046 : REPORT—1885. 
phosphorescence. Thus Giglioli met with luminosity in Abyla, Diphyes, Eudoxta, 
Praya and Aglaismoides. Dr. Bennett! has also observed luminosity amongst the 
Coralligenous Actinozoa; the grazing of a boat on a coral reef causing a vivid 
stream of phosphoric light. Similar observations were made on Madrepores by 
Giglioli,? the light in this case being bright greenish and enduring some minutes. 
Amongst the Alcyonarians the luminosity of the common Sea-Pen (Pennatula 
phosphorea) has been long known, and was studied by Gesner, Bartholin, Adler, 
and others. In the earlier part of this century Grant gave the oft-quoted descrip- 
tion,* in which he pictures a Pennatula ‘with all its delicate transparent polypi ex- 
panded and emitting their usual brilliant phosphorescent light, sailing through the 
still and dark abysses by the regular and synchronous pulsations of the minute 
fringed arms of the whole polypi.’ But it ought to be balanced by his concluding 
statement, that the sea-pens are probably stationary, or ‘lie at the bottom, and 
move languidly like Spatangi, Asterize or Actinie.’* Edward Forbes again observed 
that the light proceeded from the irritated point to the extremity of the polypiferous 
portion, and never in the opposite direction. As Dr. George Johnston tells us, 
Forbes induced Dr. George Wilson to test, along with Professor Swan, the polyps 
during phosphorescence by a delicate galvanometer, but without result. He 
thought the luminosity was due to a spontaneously inflammable substance. 
More recently a series of interesting observations were made by Panceri on the 
structure and physiology of the luminous organs of this form. His conclusions 
are (1) that the light emanates from the polyps and zoids; (2) that the 
phosphorescent organs are the eight white cords adhering to the outer surface 
of the stomach, and that these are chiefly composed of cells containing a substance 
of a fatty nature, the oxidation of which causes the light. Panceri’s conclusions 
further considerably modify Forbes’s views about the direction of the waves or 
points of light. He supposes that the elements which stand in the place of nerves 
are capable of producing in the luminous batteries of the polyps a momentary oxida- 
tion—more rapid and more intense—accompanied by phosphorescence. Like those 
examined by Professor Milnes Marshall,? the specimens at St.. Andrews, after 
irritation, show a series of brilliant coruscations which flash along the rows of 
polyps in a somewhat irregular manner. 
Two other Alcyonarians, Funiculina and Umbellularia, are equally phosphores- 
eent. Though the former is familiar enough to some of the long liners of the 
outer Hebrides and west coast, it is rare that either is procured for scientific 
investigation. Fwniculina quadrangularis, according to Forbes,‘ gives out a vivid 
bluish light, which comes from the bases of the polyps, and appears to be connected 
with the reproductive system. Sir Wyville Thomson? describes the specimens pro- 
cured in the ‘ Porcupine’ as resplendent with a steady pale lilac phosphorescence 
like the flame of cyanogen; and always sutfliciently bright to make every portion 
of a stem caught in the tangles distinctly visible. The same zoologist mentions 
that the stem and polyps of Umbellularia are so brightly phosphorescent, that 
Captain Maclear found it easy to determine the character of the light by the 
prey wie It gave a restricted spectrum sharply included between the lines 6 
and D. 
Besides the foregoing Alcyonarians, Jsis and Gorgonia have been indicated as 
likewise phosphorescent. Dr. Merle Norman and Dr. Gwyn Jeffreys (whose death 
since the last meeting of the British Association is a serious loss to science) 
mention a beautifully luminous Js’s on board the French ship * Le Travailleur ’ ; 
and Sir Wyville Thomson,’ with the facile and genial pen which characterised the 
1 Gatherings of a Naturalist, p. 69. 1860. 
* Atti della R. Accad. d. Se. di Torino, vol. v. p. 502. 
* Brewster's Edin. Journ. vol. vii. p. 330. 1827. 
* Certainly the specimens in the St. Andrews Marine Laboratory were very 
helpless. 
° Report on the Oban Pennatulide, p. 49. Birmingham, 1882. 
® Johnston’s Brit. Zooph. vol. i. p. 166. 
7 Depths of the Sea, p. 149. 
8 Atlantic, vol. i. p. 151. 9 Ibid. vol. i. p. 119. 
