THE MARINE AQUARIUM 341 



Fishes of the herring tribe sprats, whitebait, etc. will 

 not live, nor will the sand-eels. 



Of molluscs, the TrocJii and the Littorinas live well, not 

 so the Limpet another puzzle, for this one would imagine 

 the hardiest of all, but as a rule a week or two is its lease 

 of life in an aquarium. 



It is a good plan to have a glass syringe, and with this 

 draw up some of the water from the aquarium, and squirt 

 it back with force from an inch or so above the surface, 

 until the water sparkles. This, if done daily, will greatly 

 enhance the chances of success. 



If arrangements at home will admit of such plan, an 

 aquarium through which the water circulates is the best 

 of all. A reserve tank is placed at an elevation above the 

 aquarium, and the water is allowed to flow through a glass 

 tube drawn to a very fine point into the aquarium, pre- 

 ferably striking the surface from an inch or so distance, 

 so as to aerate it, as I said just now could be done with 

 a syringe. 



There must be an overflow arrangement to the aquarium, 

 the water falling into a vessel on the floor, from which it is 

 to be transferred, as occasion requires, to the upper tank. 



With either this circulating plan, or with attention to 

 the few hints I have given in regard to a non- circulating 

 one, there need be no difficulty whatever in keeping at home, 

 and under daily observation, some of the most beautiful 

 denizens of our rock pools. 



The beautiful plumed worms figured on page 85 can be 

 kept with the minimum of attention, and so can most of 

 the beautiful zoophytes, and many of the polyzoa. 



If there is plenty of vegetable growth in the aquarium 

 there will be multiplication of microscopic animals sufficient 

 for their food. 



After the many elaborate plans that have been from time 

 to time published on the marine aquarium I am afraid that 



