ARTIFICIAL ROCK-WORK. 



Half-a-dozen finger-glasses, sncli as are generally 

 placed upon the table after dinner, will be found in- 

 valuable, and for containing small specimens, adapted 

 to microscopical examination, even preferable to vessels 

 of larger size. Let one of these be filled three-parts 

 full of fresh and pure sea-water strew the bottom 

 with a few small stones and bits of rock, on which are 

 growing Confervse and young Sea- weeds in a state of 

 vigorous growth, and you at once have an aquarium 

 fitted for the reception of an infinite variety of in- 

 teresting objects. Hydras and Corynse, Sertularian 

 and Tubularian Zoophytes, Crisise, Bowerbankia3, and 

 the whole host of Polyzoa, the delicate Tubularia, and 

 the many-polyped Anthozoa, here grow luxuriantly, 

 and may be kept for months under examination. 



In the arrangement of a large tank, one of the 

 most important features to be attended to is the in- 

 troduction, upon a miniature scale, of rock-work, 

 whereby the surface for the growth of plants may be 

 most materially increased, and a picturesque appear- 

 ance given to the aquarium, which could not possibly 

 be attained without such an expedient. A wide field 

 is here opened for the display of taste and ingenuity ; 

 it is a piece of landscape gardening upon a small scale, 

 on which every amateur may exercise his talents with 

 advantage, always keeping in view the various uses to 

 which the miniature rockery ought to be subservient. 

 The first of these, as we have already said, is to increase 

 the superficial extent of the interior of the aquarium, 

 and present a larger surface for the growth of vegeta- 

 tion, a circumstance of primary importance in the 

 arrangement; for, as we shall shortly perceive, the 



