240 



TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



The law governing the increase in weight of similarly 

 shaped bodies of increasing dimensions is that the weight 

 increases directly as the cnbe of any one of the dimen- 

 sions. Thus, if a fish is doubled in length its weight 

 ought to be increased eight times. The increase in weight 

 of fishes with even slightly-increasing length is, there- 

 fore, very great. 



Several plaice caught on the Mersey shrimping 

 grounds, and measured and weighed, gave the following 

 results : — 



Length. 



Weight. 



7 J inches. 



21 OZS. 



8 ,; 



"4 » 



9 „ 



5 „ 



10 



6 „ 



12 „ 



91 „ 



Dr. Fulton* points out, however, that the weight of a 

 fish always increases more rapidly than the above law 

 indicates. This is because the growth is unequal, the 

 fish increasing more rapidly in breadth or thickness 

 (probably the latter) than in length. 



8. Exceptionally low specific gravity of the Sea Water off 

 Blackpool. 



On November 13th, 1904, while trawling off Black- 

 pool, an exceptionally low reading of the hydrometer was 

 taken. The weather was fine and the sea smooth, with 

 an easy S.E. breeze. The surface temperature was 

 8 - G° C, and the specific gravity 1021*8 (taken with the 

 Kiel araometers. On reduction, to compensate for the 

 * An. Eept. Fishery Bel. for Scotland, 1904, pt. 3, p. 141. 



