440 MR. F. SUTTON ON THE PROTECTIVE INSTINCT IN FISHES. 
III. 
THE DEVELOPMENT OF THE PROTECTIVE 
INSTINCT IN FISHES. 
By Francis Sutton, F.I.C., F.C.S. 
Read Slst May, 1898. 
So far as I am aware very little lias ever been written or discussed 
as to the instincts and emotions of fishes. 1 suppose that they have 
generally been considered so much lower than the brutes or birds in 
this respect that very little can be said about it. 
Some naturalists I believe have gone so far as to assert that their 
existence is destitute of any kind of emotion, and that their nature 
is more of a vegetative than an animal character. But we know 
that spiny-rayed fishes, say, like the Perch, are able to manifest 
what looks like anger or ferocity by tbe prompt erection of their 
spines on being handled, or when in the act of seizing their food. 
Any one who has kept Sticklebacks in an aquarium will have 
noticed the ferocity of the little male while nesting and hatching is 
going on, and how he is constantly employed in driving away 
anything which threatens to molest his offspring. Day, in his book 
on British Fishes, alludes also to the changes in colour which some 
fishes undergo, and which appear to be influenced by emotion. 
For instance, in the case of the common Stickleback, if two of them 
fight, a strange alteration takes place in the defeated fish, his gallant 
bearing forsakes him, his gay colours fade away ; his defeat appears 
to have affected his health, and he has the dejected appearance of 
a conquered slave. The victor, on the other hand, exultant in his 
victory, becomes more resplendent than ever. This change of colour 
seems among fishes to be the most prominent evidence of anything 
like emotion, and is especially evident at the breeding season. 
Day relates a case observed in an aquarium in America, where 
a male of the Blenny tribe was kept. On the introduction of 
a fish of the same kind but of the opposite sex into the vessel, an 
