Notices of New Books, 4087 



condition. I find, on comparing notes, that Mr. Warington has pre- 

 cedence of me in instituting these experiments ; but the particulars 

 that I have above detailed of my own success were fully recorded be- 

 fore I had the slightest knowledge that the thought of such a project 

 had ever crossed the mind of any person but myself." — P. 228. 



In continuation of this highly attractive subject, the author gives 

 an Appendix of four pages, in which he recommends the production 

 and introduction of a new chemical compound called ozone. We con- 

 fess we are not prepared to admit the necessity of introducing any 

 artificial chemical element into these vivaria, neither do we believe 

 there is any advantageous result obtained from the so-called aeration 

 of the water, as practised in the beautiful glazed tanks in the Zoolo- 

 gical Society's Gardens in the Regent's Park. It is most true that 

 turbidity and great apparent impurity is observable in the water of 

 some of these tanks ; but these defects in all probability result from a 

 want of attention to the requirements of Nature. In the first place, 

 it must be admitted that in attempting to imitate a rock-pool by a 

 glazed tank, we abrogate a law of Nature in admitting the light late- 

 rally instead of vertically. Secondly, in crowding into a given quan- 

 tity of water a greater number of living beings than Nature allows, we 

 also abrogate a second law. Water to aquatic, and air to terrestrial 

 animals, are as essential as food ; and any stint in the supply inter- 

 feres with the vitality of the animal. To insure success, it is not 

 sufficient to adjust the scale adroitly and fairly between animal and 

 vegetable life, but the supply of water and of light must be made a 

 matter of nice and careful experiment. By judicious attention to this, 

 w T e shall achieve more successful and more certain results than by 

 the adoption of any artifice that Nature herself ignores. 



It is, however, abundant time for us to close this protracted notice. 

 We are sorely tempted to give still further extracts, but must refer 

 the reader to the book itself, and assuredly will he find that we have 

 only given a fair and impartial sample of a work, which is uniformly 

 excellent, amusing, and instructive. Our objection to the artificial 

 management of the vivaria is rather an objection to a received usage, 

 than to a peculiar hypothesis of the author's. 



The most important portions of the work consist of detailed obser- 

 vations on the alternation of generations in the Hydroid polypes and 

 the Medusae, on the embryogeny and metamorphosis of these and the 

 Polyzoa, and on the singular structure of the thread-cells of the Me- 

 dusas and the Actiniadae. Copious details are given of the habits and 

 economy of many species of the sea Anemones and madrepores, of the 



