Morning journal and courier., 1883-09-03
ArtfGctal Sea-ROttoms and the Chame-
 Ianu EIounder.

In describing Professor Agassiz's Labo-
 rstory" at Newport, Ernest Ingersoll says in the September Century: "The tables are
 not of large aize-about like a library desk but are firmly constructed and serviceable. They are covered with English glazed tiles, white, except two black rows at the end, furnishing opposite backgrounds to the glass
 vessel in which the, often almost invisible morsel of animal life is floating What can not readily be seen against 8 white surface
 may become plainly apparent in front of 8 black one. On the long middle tables (here-
 after describsd) Mr. Agassiz has enlarged
 upon this idea by covering them with spaces of variously colored tiles stimulating natural sea-bottoms. The clear gray does well enough for sand dark leaden gray for mud |: mostlsd castile-soap pattern in brown for pebbles; and dulse-green for sea weed. It is popular errof, or, at any rate, prevalent theughtleasness, that sea animals pay no at- tention to the sort of bottom underneath them as they move about. If this is true of any, it certainly Is not of large number of kinds. Some are confined to districts limited by one sort. of bottom because it provides their only food others because there they are safer from harm than they would be elseI where; third class perhaps from choice, or for seme reason not readily discernibie. In any case, it has been both suspected and proved that the character of the bottom has great influence, particularly in the matter of color. upon the fishes and others frequenting Q district of mud OF sand or rocky or weed grown bottom respectively. It was ID order to experiment in this direction that Mr. AARassiz invsnted and provided these imita- five surfaces, which should form an artificial bottom assembling sand, pebbles, etc., when the dish eontainiag fish or invertebrate to be; decaiyed should Sbe set upon it.
 eEsI eau mention here only one of the inter estinR results of the experiments. heAoun- der; esseyerybody knows, is an illlooking, dark colored, flat fish, which creeps close along the bottom, and frequents for the most part banks of mud, from which 1t IS almost indistinguishable. Occasionally the founder occurs in sandy districts, in which case It IS of yelloWish tinge, thongh not otherWise different from it's black neighbor Of the mud
 Taking young founders, MT. Agassiz experi-
 mented upon their power of changing color. Placing them upon the biack1sh tiles, tney
 quickly turned mud color moved thence to the ssand' tiles only 6 few moments elapsed E1afora their Ieaden skins had peied to dull yellowish white; transferred to the mimic saeasweed. in less than five minutes asgreen- ;sh hue oyerspread their skins, which would have served we'll in their natiVe, element to keen them unebserved against, mass of aIcse. As the founders grew Eoldsr, the ra- pidity and facilityiwith which these changes
 were effected leasened, and perhaps they
 would altogether cease in aged lnd1Vldusfs
 who had never practiced as turn 0oats; put
 the readiness with which the youngsters ai-
 tered their -oompJezions to suit their clrcum- atanceS. as shown. by experiments Tn thls iao- sratory, would give them high rank m part ksanpolitics."