. . were” 
the lif ps afi 
at present no reliable data for the foundation of a theory as to 
the functions of luminosity, especially in relation to food. Ne 
386 General Notes. [ April, 
same author mentions that Lesueuria has a very peculiar bluish 
light of an exceedingly pale steel color, but very intense. Giglioli, 
again, found that the beautiful riband-like Cestus shone with a 
reddish-yellow light, but in Eucharis the latter was intensely 
blue. In the Chetopteride the phosphorescence is remarkably 
beautiful, bright flashes being emitted from the posterior feet. 
Marine phosphorescence has some of its most striking examples 
among the Tunicates. One of the best known instances is that of 
Pyrosoma, the light from which has been so graphically described 
. Péron, Professor Huxley, and other naturalists who have 
had an opportunity of observing it. It proceeds in each member 
of the compound organism from two small patches of cells at the 
base of each inhalent tube. Phosphorescence in living fishes 
appears to have been accurately observed within a comparatively 
recent date, though the luminosity of dead fishes has been known 
from very early times, and has been the subject of many interest- 
ing experiments, such as those of Robert Boyle on dead 
whitings, and Dr. Hulme on herrings. I do not mean to say 
that the literature of the so-called phosphorescent fishes is scanty, 
for it extends from the days of Aristotle and Pliny to modern 
fishes entered by Ehrenberg in his list it is hard to say that one 
is really luminous during life. In many cases it is probable that 
the supposed phosphorescence of large forms, such as swordfishes 
and sharks, has arisen from the presence of multitudes of minute 
phosphorescent animals in the water, just as the herring causes a 
gleam when it darts from the side of a ship. Professor Moseley, 
for instance, observed in the Challenger that when large fishes, 
porpoises, and penguins dashed through phosphorescent water it 
was brilliantly lit up, and their track marked by a trail of light. 
The same feature is observed in hooked fishes, and it is known 
that fishermen are doubtful of success when the sea is very phos- 
phorescent, for the presence of the net in the water excites the 
- luminosity and scares the herring. One of the most striking 
-instances of phosphorescence in living fishes is that of the lumi- 
S nous shark (Squalus fulgens), found by Dr. Bennett. This is 4 
small, dark-colored shark, which was captured on two OF three 
occasions at the surface of the sea. It emitted without irritation 
a vivid greenish luminosity as it swam about at night, and it shone 
_ for some hours after death. The phosphorescence appears to 9% 
due toa peculiar secretion of the skin. The eyes of the shark 
more prominent than usual in such forms. A survey o 
e-histories of the several phosphorescent grou 
_ phosphorescent form is more generally devoured by fishes oF 
animals than that which is not; and, on the other hand, the 
-= 
