214 



SCIENCE. 



[VuL. XV. No. 374. 



kingdom, but with special reference to those living forms which 

 constitute the whole aquarial exhibit. These collectibns, being 

 an introduction to the larger display, should occupy one room, 

 serving also as the vestibule or entrance-hall in the main build- 

 ing. 



2. The correlations between certain structures and parts in ani- 

 mals, and their habits and natural surroundings, can be illustrated 

 by placing plants and animals that live on muddy, sandy, grav- 

 elly, or rocky parts of our own shores in separate aquaria, prop- 

 erly arranged and furnished. The suitability of organisms to the 

 work they have to do could be illustrated in this and other wa.\s, 

 and clear ideas of one of the fundamental laws of organic modifi- 

 cation's presented to intelligent visitors and students. 



3. The extraordinai-y modifications which have taken place in 

 the struclure of the descendants of aii breathing land animals, in 

 order to fit them for life in the sea, would be illustrated in the 

 aquaria and also in the salt water ponds. These would be used 

 for such seals, cetacea, and other marine animals as are either too 

 large to be accommodated in tanks in the buildings, or which can 

 be most appropriately exhibited in such enclosures. Adaptations 

 equally fitting and instructive are found in birds which live upon 

 the sea or its borders; and examples of these forms would be 

 shown in the same ponds, or in appropriate places upon their 

 margins. 



4. It is well known that the distribution of plants and animals 

 is limited more, perhaps, by temperature than by any other single 

 cause. It is practicable to illustrate this great law of distribution 

 with suitably constructed and properly ari-anged aquaria, stocked 

 and kept supplied with animals and plants taken at moderate 

 depths upon our own coasts. The problems connected with ob- 

 taining and handling animals gathered at great depths present 

 difficulties with which no garden should attempt to cope until it 

 is completely organized. 



5. Faunal collections would compose the greater bulk of the 

 marine aquaria. It is intended lo group these together in such a 

 way as to represent the association of the forms in their respec- 

 tive habitats. No attempt, of course, would here be made toward 

 systematic grouping, but very dissimilar forms would be asso- 

 ciated together, bringing prominently into view the geographical 

 distribution of types. In one room of suitable size aquaria would 

 be devoted solely to the marine plants and animals of the North 

 Atlantic, from Cape Cod northward. As a part of this collection 

 a series of aquaria would be maintained for the exhibition of the 

 commoner plants and animals occurring on the coast of Massa- 

 chusetts. These forms could be permanently supplied, and, be- 

 ing named and described in a proper guide book, would be of 

 great interest to all persons living on the seashore. The fauna 

 south of Cape Cod is in large part easy of acquisition, and could 

 also be well represented in separate series of aquaria. The fauna 

 south of Cape Hatteras and that of the western coasts of the 

 United States, and other faunas, could also be exhibited, as op- 

 portunities presented themselves, either to a limited degree or 

 more or less extensively, if the future progress and success of this 

 division warranted the extension. 



II. Fresh Water Aquarium. 



It is obvious that an epitome collection is as desirable for the 

 explanation of the relations of fresh-water -plants and animals as 

 of the marine. 



1. The society would therefore form an epitome collection simi- 

 lax to that planned above for the Marine Aquarium ; but this 

 would necessarily differ in the details of its composition, fresh- 

 water plants and animals being used instead of marine types. 

 The adaptations of the structures of organisms to an aquatic ex- 

 istence would be exhibited by means of preparations of the gills, 

 etc., as in the corresponding marine collection ; but special adap- 

 tations to a fresh-water existence— such as the mode of reproduc- 

 tion of sponges, bryozoa, and some crustaceans by means of win- 

 ter buds; the effects of desiccation upon some of these, and their 

 mode of transportation from pond to pond; the contrasted 

 structures of corresponding fresh-water and marine shrimps; the 

 peculiarities of the batraohians, showing the transitions from a 

 purely aquatic to a terrestrial type; and similar classes of facts^ 



would be prominently illustrated. The fresh- water faunas of the 

 globe are all secondary, or derived mainly from the marine- 

 faunas. This can also be approximately demonstrated in the 

 epitome collection by placing side by side a certain number of 

 marine and fresh-water animals in series or in pairs, including 

 occasionally some fossils, in order to compare the existing Amia^ 

 gar pikes, etc., with their marine but now extinct ance.-tors. 



2. Some of the most important results of research bearing upon 

 the evolution of organisms have been attained by means of experi- 

 mentation, and it is of the greatest importance for educational 

 purposes that illustrations of such facts should he made accessible 

 to teachers and students. The council would therefore aim at 

 the repetition of some of these experimental observations, and 

 make permanent exhibitions of the results. For example: a series 

 of aquaria could be maintained, showing the gradual modification 

 of the brine shrimp in passing from a saturated solution of salt, 

 through ordinary salt and brackish waters, to a final lodgement in 

 purely fresh water, where it becomes transformed into a well- 

 known fresh-water type of crustacean; another series repeating 

 Semper's experiments upon the snail, Lymncea stagnalis; and 

 still others showing the results of experimentation upon the de- 

 velopment of the axolotl, salamanders, etc. This department 

 would also include aquaria for thp exhibitioaof the animals and 

 plants now living in mineral or hot springs, the Caspian and Dead 

 Seas, and other anomalous and more or less isolated positions, 

 such as caves and subterranean rivers. 



3. Fresh-water plants and animals are not wholly derived fron^ 

 the sea: many of them are modified descendants of terrestrial or- 

 ganisms that have changed their habitat and become suited to an 

 aquatic existence. Some of the ponds would be used to exhibit 

 this important fact, since in them the larger air-brealhing ani- 

 mals that live on or in the fresh waters — such as the swimming 

 and wading birds ; the batrachians (frogs, salamanders, etc.); the 

 reptiles (snakes, turtles, and alligators); beavers, muskrats, and 

 possibly larger representatives of the mammalia from the tropics, 

 such as tlie hippopotamus — could be confined. Some of these 

 ponds would also be devoted to the exhibition of the Liliacece and 

 other plants, which, although originally truly terrestrial and 

 flowering plants, have become more or less modified and fitted for 

 aquatic life. The huge leaves^and flowers of the Victoria regia, 

 and the lovely color of many of these annuals floating upon the 

 glassy surface of the water, and framed in a shore growth of 

 rushes and grasses, would form pictures of rare beauty and at- 

 tractiveness. 



4. Insects, although as a whole purely terreslrial and aerial, 

 contain a number of groups that pass either a portion or the whole 

 of their lives in water. An insectary would therefore be estab- 

 lished, furnished with aquaria, placed in the midst of suitable 

 plants, and suiTOunded by ample cages of netting for the confine- 

 ment and display of the adults after they have passed through 

 their transformations and have begun to fly. This part of the 

 exhibit could be made exceedingly instructive by means of a 

 printed guide, explaining the transformations of the insects shown 

 in the aquaria and cages. 



.5. The fauna of our own fresh waters is apt to strike one at 

 first as uninteresting: but it contains sponges, especially interest- 

 ing to the public on account of their effect on the water-supply; 

 many microscopical plants that can be cultivated in masses, so as 

 to be seen by the unassisted eye; large bryozoa, such as Pectina- 

 tella, growing in heads like a brain-coral ; bivalves and snails of 

 respectable size; several interesting species of batrachians; and 

 many fishes of remarkable structure and habits. The council 

 would therefore bring together a series of aquaria exhibiting the 

 animals of the fauna of New England and eastern Canada, and 

 also keep in view the idea of explaining their more obvious rela- 

 tions to the water-supply of our cities. The fauna of the inland 

 waters of the western and southern parts of North America is ac- 

 cessible, and should be shown, in so far as the more prominent 

 forms are concerned, in a separate series of aquaria. Opportuni- 

 ties will perhaps be offered in the future for the acquisition of the 

 larger and more interesting organisms of other faunas. These 

 can be exhibited, provided the future success of this division jus- 

 tifies an extension of the plan. 



