354 REPORT— 1897. 



and to confer upon him and his colleagues various orders of dignity and 

 academic honours. Among the numerous addresses presented to Professor 

 Dohrn, one, subscribed by more than nineteen hundred naturalists and 

 philosophei-s from all parts of the world, is sufficient to indicate the esteem 

 in which the Zoological Station is universally held. In the course of an 

 eloquent speech Professor Dohrn specially acknowledged his gratitude and 

 indebtedness to the British Association for their support, which has ex- 

 tended from the early critical period of the station's existence up to the 

 present time. 



The progress of the various publications undertaken by the station is 

 summarised as follows : — 



1. Of the ' Fauna und Flora des Golfes von Neapel' the monographs 

 by Dr. G. Jatta on 'I Cefalopodi, Sistematica' (pp. 268, 31 plates), and 

 by Dr. H, Ludwig on 'Seesterne' (pp. 491, 12 plates), have been pub- 

 lished. 



2. Of the ' Mittheilungen aus der zoologischen Station zu Neapel * 

 vol. xii. part iii., with 7 plates, has been published. 



3. Of the ' Zoologischer Jahresbericht ' the whole 'Bericht'for 1895 

 has been published. 



4. A new and greatly revised English edition of the ' Guide to the 

 Aquarium ' has been published. 



The details extracted from the general report of the Zoological Station, 

 which have been courteously furnished by the officers, will be found at 

 the end of this report. They embrace lists (1) of the naturalists who 

 have occupied tables since the last repoi't, and (2) of the works published 

 during 1896 by naturalists who have worked at the Zoological Station. 



I. Report on the Occupc Hon of the Table. By Mr. H. M. Yernon. 

 The Conditions of Animal Life in Marine Aquaria. 



I was originally appointed to the British Association table at Naples 

 for the months of April and May, but my term was subsequently extended 

 to the end of June. My object in coming to Naples was to continue some 

 work I had been engaged upon during a previous stay at the Zoological 

 Station. This work consisted in an investigation upon the effects of 

 environment upon the development of Echinoderm larvse. At the present 

 time I am endeavouring to elucidate something as to the conditions of 

 Animal Life — especially as regards those appertaining to Marine Aquaria 

 — by the help of these larvge, which are obtained very readily by means 

 of artificial fertilisations. 



The work consists of two more or less distinct parts — first, of the 

 growing of the larvae of Strongylocentrotus lividus under various condi- 

 tions, and then preserving and measuring them under the microscope, so 

 as to determine what change, if any, has been produced in their size by 

 the different environmental conditions ; and secondly, of the analysis of 

 the various specimens of water in which the larvae are allowed to develop, 

 so as to determine how the degree of organic impurity of the water affects 

 the growth of the larvje, and how this impurity may be most effectually, 

 as judged by both chemical and physiological standards, removed. 



The analyses of the water thus far made have consisted in determining 



