TRANSACTIONS OF SECTION D. 1049 
mucus exuded by the animal can be drawn out as bluish-purple fire of great in- 
tensity, which, besides, now and then gleams along the edges of the wing-like 
processes, and illuminates the surrounding water. A very characteristic odour, 
somewhat resembling that produced by phosphorus in combustiou, is given out 
by the animal during such experiments. In this connection it may be observed that 
Quoy and Gaimard mention that an odour similar to that around an electric 
machine is given out by luminous marine annelids. 
Amongst the Terebellide, as first shown by Grube, none excel the genus Polycirrus 
in the brightress of the phosphorescence and the ease with which it is elicited. 
Mere blowing on the water of the dissecting-trough suffices to cause in the British 
Polycirrus the most vivid pale bluish luminosity, which gleams for a moment along 
every one of the remarkably mobile tentacles. Long before Grube, however, had 
discovered the phosphorescence of Polycirrus, our patient and laborious countryman, 
Sir J. Graham Dalyell,! had noticed it in the group, for he mentions that when 
irritated Terebella jigulus gives out the most copious blue refulgence, intermingled 
with a reddish flame. Another member of this family, viz., Thelepus, is only 
faintly phosphorescent in life, but when decomposition has made progress it gleams. 
in the vessel with a pale lambent light, somewhat like phosphorus in air. 
In the pelagic Tomopteride certain peculiar structures on the parapodia, 
formerly supposed by some to be eyes, and by others simply glandular organs, were 
lately found by Professor Greeff? to be luminous organs, which, though glandular, 
have a considerable nervous supply, including a ganglion. 
Panceri’s observations on the luminous annelids of Naples and the peculiar 
type Balanoglossus (Enteropneusta) have recently added considerably to our know- 
ledge of the subject. He specially describes, in Chetopterus, the structure of the 
phosphorescent glands in the great pinnules and other parts, which produce the 
luminous mucus. With some reason, he concludes that two kinds of phosphor- 
escence are present in annelids, viz.,one which is the result of purely nervous 
action, and another which is due to this plus a luminous secretion. 
A Turbellarian, viz., Planaria retusa, was mentioned by Viviani*? as luminous, 
but this feature appears to be rare in the group; and the same may be observed of 
phosphorescent Rotifers, one of which (Syncheta baltica) was described by 
Ehrenberg.* Giglioli,® again, records a Sagitta which showed a feeble luminosity 
in the posterior region of the body. 
The minute forms amongst the Crustacea (chiefly Copepoda) were recognised as 
phosphorescent by Athanasius Kircher in 1640, and have been mentioned by most 
authors who have alluded to the subject since that date.° Thus Viviani gives seven 
species from the shores of Genoa, and Tilesius no less than nineteen luminous crus- 
taceans from Krusenstern’s voyage. Dr. Baird describes the light given out by 
those met with in his cruises as brilliant in the extreme, and Vaughan Thompson 
added considerably to our knowledge of Sapphirina and of the luminous schizopods, 
an example of which had been discovered by Sir Joseph Banks, and described by 
Macartney.7’ Most authors agree that the minute forms, such as the Copepods, give 
a sparkling appearance to the surface of the water. The light in these, according 
to Lesson, proceeds from glands placed on the sides of the thorax; while Giglioli 
found the luminous organ of the cosmopolitan Sapphirina in the anterior part of the 
thorax. On the other hand, Captain Chimmo ® thought it was decomposing food 
in the stomach, and Professor Moseley ® in certain cases entertained a similar 
opinion. The phosphorescence of the Kuphausiidee was a prominent feature in the 
voyage of the ‘Challenger,’ brilliant flashes being emitted on capture from a series 
of spots along the trunk and tail. Mr. Murray also met with a diffused light in 
the Farée channel when dredging in the ‘Triton,’ and he attributed this to the 
1 Powers of the Creator, vol. ii. p. 210. 
2 Zoologischer Anzeiger, 1882, p. 384-87. 3 Op. cit. p. 13. 
4 Op. cit. p. 128. ® Op. cit. p. 498. 
® Professor G. S. Brady has recently observed phosphorescence in some Pontelline. 
7 Phil. Trans. 1810, as ‘ Cancer fulgens,’ 
' ® Huplectella, &c. 1878. 
° Op. cit. p. 574. (Naturalist on the * Challenger.’) 
