86 POPULAR SCIENCE MONTHLY. 



fauna of the tide-pools, neglected by almost all collectors. As the tide 

 goes down, especially on rocky capes which project into the sea, myriads 

 of little fishes will remain in the rock-pools, the algse and the clefts 

 of rock. In regions like California, where the rocks are buried with 

 kelp, blennies will lie in the kelp as quiescent as the branches of the 

 algse themselves until the flow of water returns. 



A sharp, three-tined fork will help in spearing them. The water in 

 pools can be poisoned on the coast of Mexico, with the milky juice of 

 the 'Hava' tree, a tree which yields strychnine. In default of this, 

 pools can be poisoned by chloride of lime, sulphate of copper, or, if 

 small enough, by formaline. Of these, a solution of commercial 

 chloride of lime, yielding free chlorine gas is cheapest and most service- 

 able. By such means the contents of the pool can be secured and the 

 next tide carries away the poison. The water in pools can be bailed 

 out, or better emptied by a siphon made of small garden hose or rubber 

 tubing. On rocky shores and about coral reefs dynamite can be used 

 to very great advantage, if the collector or his assistant dare risk it, 

 and if the laws of the country do not prevent. Most effective in rock- 

 pool work is the help of the small boy. In all lands the collector will 

 do well to take him into his pay and confidence. Of the hundred or 

 more new species of rock-pool fishes lately secured by the writer in 

 Japan, fully two thirds were obtained by the Japanese boys. Equally 

 effective is the 'muchacho' on the coasts of Mexico. 



Masses of coral, sponges, tunicates and other porous or hollow 

 organisms often contain small fishes and should be carefully examined. 

 On the coral reefs the breaking up of large masses is often most 

 remunerative. The importance of securing the young of pelagic fishes 

 cannot be too strongly emphasized. 



Fishes must be permanently preserved in alcohol. Dried skins 

 are far from satisfactory, except as a choice of difficulties in the case 

 of large species. Dr. Gunther thus describes the process of skinning 

 fishes : 



Scaly fishes are skinned thus: with a strong pair of scissors an incision 

 is made along the median line of the abdomen from the foremost part of the 

 throat, passing on one side of the base of the ventral and anal fins, to the 

 root of the caudal fin, the cut being continued upwards to the back of the tail 

 close to the base of the caudal. The skin of one side of the fish is then severed 

 with the scalpel from the underlying muscles to the median line of the back; 

 the bones which support the dorsal and caudal are cut through, so that these 

 fins remain attached to the skin. The removal of the skin of the opposite side 

 is easy. More difficult is the preparation of the head and scapulary region; 

 the two halves of the scapular arch which have been severed from each other 

 by the first incision are pressed towards the right and left, and the spine is 

 severed behind the head, so that now only the head and shoulder bones remain 

 attached to the skin. These parts have to be cleaned from the inside, all soft 

 parts, the branchial and hyoid apparatus, and all smaller bones being cut away 



