Page:Popular Science Monthly Volume 50.djvu/32

20 a series of huge triton snails and the clustered eggs of cuttlefish. In another tank a bank of sea anemones exemplifies the large and gaudy forms common to southern waters—buff, orange, yellow, and vermilion—and there may be corals in the background, and a spectral forest of sea fans in white and violet, with a precious fringe of pink coral flowering out in yellow, starlike polyps. There may, again, be in a neighboring tank a host of ascidians, those curiously degenerate vertebrates whose stock could not have been widely unlike the ancestral stem of the fishes. Delicate, transparent, solitary forms, like the lanky Ciona, contrast with the deeply crimson Cynthia and the huge and mottled masses of many compound forms. Swimming about them may be chains of Salpa, and occasionally a number of Amphioxus, the latter to be seen only from time to time as they burrow out of the sandy bottom, flurry about as if in sudden fright, and quickly disappear. Variety is one of the striking characters of the arrangement of neighboring tanks. In one, brilliant forms outvie the colors of their neighbors. In another are examples of the closest mimicry of animals to their surroundings, where the stranger has often to examine long before in the seemingly empty tank he can determine on every side the hidden forms. Thus one by one will come into his view the rays and flounders, whose colors render them almost indistinguishable from the gravelly bottom; next he will see the upturned eyes of the curious stargazer, which lies almost buried in the sand; then a series of mottled crustaceans, wedged about in the rocky background, or an occasional crab which wanders cautiously about, carrying a protective garden of seaweeds on his broad, flattened back. Near by will be odd-looking pipefishes and the sea horses, poised motionless in mimicry of the rough stems of the seaweeds. In a larger tank, sea turtles float sluggishly about, and coiling amid broken earthen jars are the fierce-looking, snakelike, sharp-jawed murries, to suggest Roman dinners and the slave-eating experiments of the lordly Pollio.

The aëration of the aquaria is secured effectively by streams of air which are forced in at the water surface and subdivided into bright clouds of minute silvery bubbles. The tanks are cared for from the rear passageways, and the attendants are rarely seen, although it is the constant attention in the arrangement and the restocking of the tanks that has gained the aquarium its well-earned success. Illustrated catalogues in French, German, English, and Italian enable the stranger better to appreciate his visit.

—The Amsterdam Aquarium is the most recent of the larger aquariums in Europe, dating from 1880. It was then opened, under the directorship of Dr. G. F. Westerman, as an