OUR METHODS OF COLLECTION AND 

 OBSERVATION 



The difficulty or downright impossibility of collecting 

 marine organisms, especially fish, in a zone rich in coral 

 formations with the conventional indirect methods of the 

 trawl-net, fixed-net, bow-net, hook, etc., obliged us to collect 

 directly, swimming underwater in apnoea (free-air immer- 

 sion) or using the oxygen apparatus — by far the best method. 

 Echinoderms, crustaceans and in general all benthotic 

 organisms that were fixed or moved very little, were collected 

 by hand, occasionally gloved for protection against organisms 

 that stung, like millepors, anemones, etc. Moving animals 

 were captured by other means, the most important of these 

 being the underwater gun. Using this weapon we were able 

 to catch sharks and other fish which even the native fisher- 

 men said could not possibly otherwise be caught. 



The gun proved suitable for taking medium-sized and big 

 fish, but small ones had to be caught by means of thin metal 

 lances tied to a sling. For the minute fish of a couple of 

 inches long we had to resort to small charges of gelatine. 

 Unnecessary killing was avoided by limiting this to a range 

 of from eight to ten feet. 



With this system alone it was possible to collect fish which 

 in the past have avoided capture or escaped notice and 

 which are therefore of special interest to the scientist. In this 

 way we collected numerous examples belonging to the most 

 varying species of the families Pomacentridae, Antidae, residents 

 of the various madrepore ramifications, Labridae, Gobidae, 

 Blennidae, Scorpaenidae, Apagonidae, Syrignathidae, etc. 



228 



