341 



The Relations between Marine Animai and Vegetable 



Life. 



H. M. Vernon. 



Contents. 



pag. 



Introduction 342 



Method of Experiment 343 



Part 1. The Purification of Water by Yege table Life. 

 The Effects of Algie on the Purification of Water. 



a. Tlie Effect of Ulva latissiinu 34Ü 



b. The Effect of other Kinds of Alg* 349 



The Effects of Diatomacea? and Minute Algte. 



a. The Effect of Filtration through Sand 352 



b. The Effect of keeping the Water in Diffuse Dayliglit .... 301 

 Tlie Influence of Bacteria on the Purification of Water. 



a. The Effect of Siinlight 3G3 



b. The Effect of keeping the Water in Darkness 369 



e. The Effect of Filtration through Asbestos 381 



d. Tiie Effect of Heating the Water 382 



e. Other Bacteriological Results obtained 385 



Part 2. The Fouling Effects of Animai Life on the Water. 



The Effects of Animala in General 389 



The Effects of Echinoids 392 



The Effects of Plutei 397 



The Effects of Certain Saits on Larvai Growtli 399 



Part 3. M iscel laneous. 



The Effects of Aeration on the Purification of Water 401 



The Nitrites present in the Water 4(i3 



The Arm-Length Measurements 4U6 



The Chemical and Physical Properties of Aquarium Water 411 



Practical Conclusions 414 



General Conclusions 417 



Summary 419 



Table 422 



Mittbeiluugen a. d Zoolog. Station zu Neapel. Bd. 13. 23 



