MILLPORT MARINE BIOLOGICAL STATION. 19 
expressions, despite having ‘‘immovable eyes and a fixed osseous 
face.”’* When exvecting food, they display considerable vivacity ; 
when being chased by larger fish, their whole appearance and 
actions are suggestive of fear. I have seen a Cobbler (Cottus 
scorpius), of a bright red colour to match Melobesia, jumping, 
quivering with excitement, erecting and spreading his magnifi- 
cently spotted fins before a more sombre-coloured female, his: 
colour alternately growing dull and bright meanwhile; some of 
this change of colour was probably due to alterations in the 
incident angle of light or vision. 
During the end of August, September, and often later, there 
are large shoals of small Herring, about two and a half inches 
long, all over this district; their presence is generally indicated 
by a screaming flock of Gulls and their allies, who destroy the 
fish by thousands. If one rows out to such a place one finds 
the water glistening with the scales of the young Herring. 
Besides the birds, Whales, Porpoises, and other fish are con- 
tinually decimating these shoals. The Bottle-nosed Whale 
follows them, rises right through them, and must catch hundreds 
at a time; I am told that incidentally they sometimes catch a 
Gull or two as well, but the Gulls are wary, and detect the 
Whale very quickly, and rise screaming just before him. These 
young Herring are often packed in dense, almost solid, masses. 
Four years ago I caught with two dips of a net eight inches wide 
and four deep one hundred and sixty-one young Herring from 
one of these packed shoals. 
The colours of fishes vary, generally according to their sur- 
roundings, becoming light on a light background, and dark 
against dark. I find that fish kept in the dark become pale, 
whatever the nature of the background; Saithe, Cobblers 
(Cottus), and Gunnells (Pholis gunnellus) gave marked results, 
but Wrasses (Ctenolabrus and Labrus) did not make such an 
obvious change. On examining the fishes in the tank-room at 
night I then found that these species regularly became paler at 
night; the Pogge (Agonus) and the 3-spined Stickleback also 
showing the same change. Wrasses again showed less change, 
and I could not detect any change in Conger. This agrees with 
* ‘Journal of the Linnean Society,’ vol. xv. F. Day on “ Instincts and 
Emotions in Fish.” 
c 2 
