44 77 hj Action of Light upon the [January, 
diamond-beetle — are as remarkably brilliant as others are 
conspicuously sombre. 
On the other hand, attention is drawn to the Chrysome- 
lidse, to which the redoubtable Colorado beetle — vilely called 
the potato-bug — belongs, a family very richly and brightly 
coloured. Their larvae are aCtive, and they are thus through- 
out their lives exposed to the sunshine. 
Among the animal population of the seas and rivers, also, 
we meet with faCts, not a few, difficult to reconcile with the 
hypothesis under examination. It must be admitted that 
in all waters, save the very shallowest, the amount of light 
enjoyed must be very decidedly less than that which falls 
upon the surface of the land in similar climates ; yet we do 
not find that the denizens of the waters are, as a general 
rule, less vividly coloured than those of the dry land. On 
the contrary, fishes, crustaceans, molluscs, besides aquatic 
forms lower in the scale of existence, such as the sea- 
anemones, display all the colours of the rainbow in a purity 
and in a profusion rivalling what we observe in the most 
gorgeous birds and inserts. We admit that splendid oceanic 
forms are more abundant in tropical waters than in higher 
latitudes, and also that in a majority of cases the inmates 
of shallow waters are more vividly colcured than the 
dwellers in deeper, and consequently darker seas. But what 
must be inferred from the following observations, extracted 
from a paper by H. N. Mosely, late Naturalist to the 
Challenger Expedition, read before the Linnean Society on 
February 15th, 1877 ? — “ A species of Edwardsia from 
600 fathoms has undergone but little modification from the 
littoral form. The Cerianthus from 2750 fathoms is like its 
shore-brethren. Thus one species is found in shallow water 
at the Philippines, under the full glare of the tropical sun, 
while another species exists at 3 miles depth, where solar 
rays never penetrate, and where the water is at freezing- 
point. The deep sea-anemones retain vivid colours in the 
dark.” 
This faCt is very suggestive. It agrees ill with the often- 
expressed view of teleologically-disposed naturalists, that 
all the brilliant hues of animal and vegetable life have been 
called into existence for man’s delectation : but no less does 
it clash with the conclusions drawn from the paleness and 
obscurity of certain nocturnal, subterranean, or cave-haunting 
animals, such as the Coleopterous larvae to which we have 
referred, wood-lice, crickets, &c. Light, it would seem, is 
not the sole condition for the production of positive colour; 
nor are the dwellers in darkness necessarily restricted to a 
