230 Notices on Species of Stickleback. 



successive appearance and disappearance of coloured spots in 

 the mantles of several of the cephalopode mollusca. 



[For lucid information on the structure and secretions 

 which actuate the colours in Mollusca, see G. J. in our 

 V. 618—622.] 



Fishes. — Fishes and Reptiles have the Power to assimilate, in 

 some degree, their Colour to that of the Objects about them, to 

 the end of concealing themselves from their Enemies. — I observe, 

 in VII. 599., in some interesting remarks by O., on the habits 

 of the stickleback, that he notices, with some surprise, the 

 rapid change of colour which takes place in some individuals 

 of this genus on being removed from one vessel to another. 

 I beg leave to call his attention to the fact, that various fishes 

 and reptiles possess the remarkable power of accommodating 

 their colour to that of surrounding objects. Some interesting 

 experiments on this subject were detailed a year or two since, 

 in Jameson's Journal, by my friend Dr. James Stark of Edin- 

 burgh, who imagines, and, I think, with great plausibility, that 

 this power is a provision of nature, whereby they are enabled, 

 in a degree, to conceal themselves from their enemies by 

 assimilating their colour to that of the bottom of the stream. 



I A Species of Stickleback which has Four Dorsal Spines (Gas- 

 terosteus tctracdnthus Cuvier) has been captured in Scotland.'] — 

 While on the subject of sticklebacks, allow me to add that 

 another species has been added to our fauna by Mr. John 

 Stark of Edinburgh, found in that neighbourhood with the 

 commoner species. It appears to be identical with Cuvier's 

 Gasterosteus tetracanthus, under which name it will probably 

 appear in Mr. Yarrell's forthcoming work on British fishes. 

 — W. C. Clapham lioad, Dec. 15. 1834. 



[A brief mention of this species is made in Jameson's Jour- 

 nal, No. 35., January, 1835. At a meeting of the Wernerian 

 Society, on March 15. 1834, Professor Jameson described it, 

 and exhibited drawings of it. It has four dorsal spines (im- 

 plied in the term tetracanthus). Mr. Stark had detected it in 

 the ditches of Hope Park.] 



It may be that Six Species of Stickleback are known to occur 

 in Britain. — Mr. Yarrell has made known, in III. 521 — 523., 

 that three three-spined species, the Gasterosteus trachurus, 

 semiarmatus, and leiurus, of the Histoire Naturelle des Pois- 

 sons of Messrs. Cuvier and Valenciennes, occur in Britain ; 

 and he has also made known, in III. 521 — 523., by descrip- 

 tions and figures, the distinctive characteristics of these three 

 species ; and has remarked that the three had been constantly 

 confounded under the name G. aculeatus Lin., and that, " as 

 the old term aculeatus applies equally to all of them, this ap- 



