22 POPULAR SCIENCE MONTHLY. 



junct of the famous Zoological Society of Amsterdam, Natura 

 Artis Magistra, The building itself is situated on the broad ave- 

 nue margining the Zoological Garden, and is decidedly an attract- 

 ive one, although outwardly as cold and dignified as the typical 

 municipal building, with its Roman architecture and its central 

 temple- like structure. Its large size, about a hundred yards in 

 length, has been of great advantage in the arrangement of the 

 details of the interior, permitting the decorative use of columns, 

 arches, and cornices without noticeable sacrifice of space or the 

 appearance of overcrowding. The main corridor, which the visi- 

 tor enters after he has ascended a broad white stairway, is wide 

 and stately, its marble walls and floor diffusing the light entering 

 from the large glass faces of the aquaria. The corridor is about 

 fifty yards in length, and the aquaria, twenty in all, are arranged 

 on either side, the largest measuring about thirty feet. They have 

 been admirably designed to display their collections of living 

 forms ; fishes are notably present, and on every hand their move- 

 ment is incessant, with gleams of color and changes of outline as 

 they sweep to and fro. The critical observer is particularly im- 

 pressed with the great number of fishes which have been kept 

 successfully in a single tank ; among them he recognizes the 

 prominent forms occurring along the North Sea coasts turbot 

 and sole, ling, cod, rays, and flounders even the herring and 

 mackerel, to which confinement is usually most fatal. A collec- 

 tion of fresh-water fishes is not lacking, including a number of 

 American forms, for which the director has been indebted to Mr. 

 E. G. Blackford, of New York city black bass, amia, and catfish 

 the latter strongly contrasting in size with their European 

 cousin in an adjoining tank, the giant Wels of the Danube. 

 From the extreme end of the aquarium room the visitor passes 

 into a smaller hall, circular in outline, which contains over a 

 score of table tanks displaying forms of attractive fresh-water 

 fishes and salamanders ; it is brightly lighted and pleasingly 

 decorated with a marble-tiled floor, fringed by palms and ferns. 

 From this room an entrance leads, on the one hand, into a spa- 

 cious auditorium, which is made of use in courses of popular 

 lectures, and, on the other hand, by a few marble steps, into a 

 well-lighted museum containing in several rooms a collection of 

 dried or alcoholic preparations of the typical forms of inverte- 

 brates and lower vertebrates. 



The operative portion of the aquarium includes well-lighted 

 corridors extending on either side of the main hall ; the pathway 

 along which the visitor passes has been sunken below the walls 

 of the tanks, whose shelving sides can thus be more conveniently 

 reached by the attendants. A series of darkened corridors next 

 lead into the vaulted basement containing the large storage tanks. 



