THE PUBLIC AQUAEIUM 



309 



life, or both, and how many kinds are available within reasonable 

 collecting and shipping limits. All aquariums are dependent upon 

 their own efforts in collecting and transporting. There are no sources 

 from which exhibits may be purchased. Many inland localities afford 

 but limited variety in fresh-water exhibits, Avhile the transporting of 



marine life by rail involves considerable expense and some losses in 

 transit. The keeping of marine life is dependent upon the storage of 

 sea water, its circulation and filtration, as well as heating in winter 

 if exhibits are derived from tropical waters. The keeping of fresh- 

 water forms is comparatively simple and inexpensive as compared 

 with those requiring sea water. 



