96 REV. F. A. WALKER, D.D., F.L.S., 
when the specimens have been in fresh and good condition ; 
but my belief is that this appearance is very transient, and 
does not long survive their capture and transference to 
cabinet drawers. I do not pretend to say what occasions the 
combination of green and purple, but it is possibly worth 
while to notice that short iridescent hairs of somewhat the 
same tints clothe the back of the doris or sea-mouse as it 
appears cast up upon the beach, and this consideration leads 
us to the question of colour in another order of organic beings 
—namely, fishes. In these the action of light is apparent. 
The part of the body turned towards the light is always paler 
than that which is undermost. Fishes which live on the side, 
as the sole and turbot, have the left side, which answers to 
the back, of a dark tint, whilst the other side is white. 
Nevertheless, it would appear that the fishes of the richest 
shade, in distinction to the beings inhabiting the earth and 
the air, exist where the light is more tempered, and that 
some kinds found both on the shores as well as in depths 
requiring the drag-net, are of a bright red purple in 
the latter regions, and of an insignificant yellow-brown in 
the former. Other bright objects of the deep, such as certain 
species of sea anemone, and the like, only occur at a con- 
siderable depth below the surface water, so that they cannot 
be observed at all in their natural habitat, except in some 
sea caves which the tide fills toa considerable height, only 
receding from the entrance sufficiently to allow of ingress two 
or three times a year, whereby I obtained a sight of these 
numerous and marvellous creatures studding the rocky walls. 
I shall take occasion to advert to these marine caverns again, 
so before quitting this part of the subject would merely remark 
that those who bring up gold fish know well that to have 
them finely coloured they must place them in a shaded vase 
where aquatic plants hide them from the extreme solar heat, 
and that under a hot July sun they lose their beauty. 
Similarly on a summer’s day common carp and roach, &c., 
will betake themselves to the shelter of the expanded leaves 
of the water-lilies in our ponds. A great deal of what has 
bcen above stated tends to show that it is vain to say that an 
animal is beautiful in shape or in colouring, in order to please 
the human eye; and Wallace testifies to the same truth in the 
second yolume of his Malay Archipelago, wherein on obtaining 
a specimen of the king bird of paradise, he states :— 
‘“T knew how few Europeans had ever beheld the perfect 
little organism I now gazed upon, and how very imperfectly 
it was still known in Hurope. | 
