ON THE INSTINCTS AND EMOTIONS IN EISH. 31 



Fig. 11. Ditto of Acrida viridissima, showing two sets of longitudinal muscles. 



12. The marginal disks of the Crane-fly attached to the nerve-centres: 



I', I', I", those of the legs ; pa, that of the prothoracic appendage ; 

 w, w\ those of the wings and halteres. 



13. Thorax of Goerius dens, showing the dorsal plate of the fifth segment, 



i, attached thereto and separated from the succeeding abdominal 

 ones : ps', the postscutellum of the metatborax. 



14. Vertical thoracic muscles of Mshna grandis, showing a distinct repe- 



tition, 1 2 3 4, 1 2 3 4, in each segment. 



15. The subtriangular metaphragma of Ehizotrogus solstitialis formed by 



the postscutellum of the segment, for comparison with the postscutel- 

 lum in fig. 13. 



Instincts and Emotions in Fish. 

 By Francis Day, F.L.S. 



[Bead November 6, 1879.] 



DuRiNa the last few years the instincts of brutes have received 

 much attention from biologists, while those of fishes have been 

 generally passed over. Some naturalists have not hesitated to 

 assert that the lives of the finny tribes are destitute of the joys 

 and sorrows generally appertaining to vertebrate animals, attri- 

 buting to them an almost vegetative existence. In a work lately 

 published in this country, Cuvier's low estimate of their intelli- 

 gence has again been adopted in its entirety, although during the 

 course of this century much information has accumulated point- 

 ing in an opposite direction. Irrespective of this, the ancients 

 must have had a higher opinion of the finny tribes than the 

 authors of the present time, if we are to judge from the attributes 

 they accorded to fish. 



But returning to half a century since, we find that Cuvier had 

 no very exalted opinion of the intellect of fishes, considering that 

 among all the vertebrate animals they show the least signs of 

 sensibility, which of course might be expected, as they are the 

 lowest division. Nearly or quite destitute of any voice, with im- 

 movable eyes and a fixed osseous face, their physiognomy has no 

 play, their emotions no expression, only capable of hearing Jhe 

 loudest sounds, for, condemned to reside in an empire of silence, 

 they have but small occasion for the sense of hearing. No tear 



