96 IMITATIVE COLOURING 



ascertain if, by exposure on a dark ground, the red spots would 

 not re-appear, was neglected. In talking over this question with 

 Mr. Long, the obliging manager of the Southport Aquarium, he 

 mentioned several facts respecting Hippocampi and Turbots worth 

 noting, which it is satisfactory to find quite confirm some informa- 

 tion given to M. Pouchet by the manager of the Aquarium at 

 Concarneau. He also stated that he had found the Eledone 

 exceedingly sensitive in the matter of colour changes ; a blow 

 Vv'ith the hand against the glass of the tank in which the Eledone 

 was confined, was sufficient to change its colour immediately from 

 ])ink to dark crimson. Young Squids he had also found to 

 be very sensitive, but the causes for the changes he could not 

 trace ; they appeared to change without any exciting cause 

 whatever. Incidentally he stated that the whole life of the 

 Octopus did not exeed five or six months. If that is true 

 in the case of a creature so highly organised, there appears good 

 ground for expecting great activity in its organic functions ; and 

 imitative colouring, for the purposes of protective mimicry, would 

 be of 'great value in the defence of its short but active fife. 



Respecting the Hippocampus, M. Pouchet mentions that the 

 male, after the breeding time, has been noticed to turn pale. Mr. 

 Long states that some time back, in order to brighten the appear- 

 ance of the tank in which the Hippocampus was placed, he ob- 

 tained blocks of white veined stone and placed them in the water ; 

 he was much startled next morning to find that most of the crea- 

 tures had lost their brown mottled appearance, and those which 

 had anchored themselves in front of the white blocks were so pale 

 that he at once concluded they were dead ; on removing the blocks 

 of stone they all resumed their former colour. Mr. Long's descrip- 

 tion of the changes in Turbot far exceeds anything which was seen 

 by M. Pouchet at Concarneau, and if supported by further experi- 

 ments, which he has kindly promised to carry out on my account, 

 brings us face to face with facts which will prove most interesting 

 to anyone who can investigate and satisfactorily account for them. 



The Turbots placed in the tanks of the Southport Aquarium 

 were at first all dull brown or inclining to a slaty hue, according as 

 they had been caught on a sandy or muddy bottom. Mr. Long, 

 for the purposes of giving the bottom of his tanks a cleanly 



