SEA-FISHERIES LABORATORY. 149 



always be used, and the drags should be of uniform length 

 and duration, in order that they may be as strictly as 

 possible comparable with one another. In addition to the 

 fish trawl, it would be very useful at most stations if a 

 haul of the shrimp trawl could also be taken. 



(b) Every drag should be recorded, irrespective of the 

 numbers of fish caught. A poor haul is just as important 

 for statistical purposes as a successful one. 



(c) All the fish caught should be measured, and the 

 numbers of each kind and size accurately recorded on a 

 form similar to the one appended. 



(d) A number of individuals of each of the more im- 

 portant kinds of fish— such as plaice, sole, cod, haddock 

 — from every haul should be weighed and measured 

 separately. The ovaries should then be taken out and 

 weighed, and the results recorded on the form. Any- 

 thing noteworthy in the condition or appearance of the 

 ovaries should be added. The stomachs should be opened 

 and the contents noted. 



(e) Mention should be made of any unusual fishes or 

 invertebrata taken in the trawl, and also of any special 

 abundance of common things such as star-fishes, crabs, 

 molluscs, jellyfish, zoophytes, worms, or other fish food. 

 Unusual specimens, or anything not recognised, should 

 always be preserved for examination in the Liverpool 

 Laboratory. 



II. "Plankton" (or Tow-net) Collections.— Tow-net- 

 tings should be taken along with every drag of the fish 

 trawl. One haul with a bottom and one with a surface 

 net should be made on each occasion. Also one haul 

 of the vertical net for quantitative work should be made 

 at each station. These collections should be at once 

 preserved according to instructions, and sent to the Liverpool 

 Laboratory as soon as convenient after landing. Extra 



