A Brief History of a River Tank. 39 



all were visible in an ascending series, which produced 

 an agreeable tout ensemble, and at the same time made one 

 source of water supply sufficient for the whole. This was a 

 strictly artificial arrangement, but it was perfectly successful. 

 The tanks were all well stocked with fishes, reptiles, insects, 

 etc., classified according to their habits and proclivities, and so 

 grouped that when viewed collectively, the scene was beautiful 

 in the extreme. One more instance of artificial management 

 for show purposes will, perhaps, suffice. When lecturing at the 

 Reading Institution some years ago, Ihad an accident, and spoiled 

 nearly all the sea- water that had been secured for the display. 

 But I was not to be beaten by trifles. I had enough sea-water 

 left to fill a few large shallow glass pans ; into these pans I 

 transferred the anemones, star-fishes, etc., and gave them just 

 enough water to cover them, and in the show tanks I grouped 

 the large handsome specimens of algae that had been collected 

 for the purpose, so as, with serpulas shells, rocks, etc., etc., to 

 make handsome groups, and filled those tanks with water drawn 

 from the Institutional water-butt, and kept the secret to myself 

 from that day to this. That was a perfectly successful under- 

 taking • the tanks looked beautiful by gaslight, with their grand 

 groups of algce, and as for the animals, the thin film of water 

 over them, and their recent travel and subsequent transference 

 from their places in the tanks, caused just enough of that 

 peculiar irritation which seems to be needful to cause a full 

 display of the beauties of certain of the Radiates, and the 

 audience had the advantage of beholding star-fishes, plumose 

 anemones, and other marine subjects, in the attitudes they habi- 

 tually assume when safely anchored fathom deep in ocean 

 brine. 



The natural system is an imitation of nature, not in out- 

 ward appearances merely, but in conditions. Tanks managed 

 , on the natural system may be made to have a most beautiful 

 appearance, and I flatter myself that the example I am now to 

 bring before you could not be easily surpassed for beauty, con- 

 sidering it simply as an appropriate item in a " home of taste." 

 But it is impossible to use such vessels for show purposes; 

 any disturbance of the furniture would be a violation of the 

 most essential conditions, and mere decorations are not to be 

 tolerated ; they are, in fact, forbidden by the laws on which 

 the system is based. How do we proceed to carry out the 

 natural system ? We form within a vessel or vessels a group 

 or groups of objects in imitation of rock-pools, running streams, 

 lakes, ponds, and so forth. If .it is intended to keep in any of 

 the vessels creatures that habitually dwell in mud, there must 

 be a bottom of mud for them. If retiring places and dark 

 recesses are needed, they must be built ; whatever is to be the 



