241 



Notes on Marine Aquaria. 



By H. J. Waddington. 



(Read March 23rd, 1888). 



I should hardly have ventured to read a paper on Marine Aquaria 

 did I not know that the subject is an interesting one to many 

 members of this Club. I must admit that there are two objections 

 which may be fairly raised : the first that it is hardly microscopical, 

 and the second that so much has been already said and written 

 that it is a little threadbare. To the first of these I should reply 

 that although the primary intention of keeping Marine Aquaria may 

 not be microscopical, yet if the keeping them is successful there is 

 very much to be found that is interesting to microscopists, and that 

 from the few opportunities we in London have of studying marine 

 zoology in its minuter forms, the life which is developed is com- 

 paratively new to many of us. I cannot give you a better illustra- 

 tion of this than by instancing the specimen of Hydra tuba which 

 I had the pleasure of exhibiting at our special evening meeting. 

 From the happy accident of this having developed on a loose stone 

 I have been able to watch it for many months. Seen at our meeting 

 in a small bulk of water, which was constantly shaken by the passing 

 to and fro, the tentacles of the Hydra were not fully expanded, but 

 when at rest in the aquarium they are in some cases fully 1 J inches 

 in length. They are constantly budding, so much so that the glass 

 vessel on which the stone rests is dotted all over with small Hydra. 

 A few months before their appearance the vegetation in the same 

 aquarium (an ordinary bell-glass) contained the beautiful Freia 

 elegans in considerable quantity, and a specimen of Tubularia 

 indivisa, brought from our Whitstable excursion in 1886, is still 

 flourishing. I might instance many more interesting finds, but I 

 think I have said enough to show that the subject is at least 

 collaterally microscopic. 



The remarks I have to make this evening deal with Aquaria 

 intended for Actinia and allied forms of life, and I desire that they 

 may be taken not as directions for aquarium keeping, but as 

 illustrations of what may be done under circumstances which are 



Journ. Q. M. C, Series II., No. 22. 19 



