78 
North Sea Investigations. 
(Continued.) 
By 
Ernest W. L. Holt, 
Naturalist on Staff in Charge of Investigations. 
PAGE 
I. On the Relation of Size to Sexual Maturity in Round Fish . : . 78 
II. On the Destruction of Immature Fish in the North Sea : : 5 till 
Beam trawling by large vessels : : F ° 6 bill 
Shrimp trawling : d : . 3 of Sho) 
Shore fisheries. F : : : 6 . 104 
III. Remedial Measures . : ; : ° : . 105 
INTRODUCTORY. 
I HAVE again so many acknowledgments to make for help 
received that it would be invidious to select names, whilst to 
enumerate all would unduly trespass on the space allotted to me. 
The work, as before, has been carried on at the Marine Fisheries 
Society’s Laboratory at Cleethorpes. 
I, On tHE RELATION oF SizE to SexuaL Maruritry 1n Rounp 
Fisu. 
Since the flat fishes appeared to be of more immediate importance, 
and time did not suffice for the thorough examination of both forms, 
I have deferred to deal with the round fishes until the present 
spawning season. Up to the time of writing only cod and haddock 
have been spawning, and neither species has ceased to do so. My 
records are therefore incomplete, even for these two forms, and 
especially for the last named, owing to the difficulty which has been 
experienced in procuring specimens from which the viscera have not 
been removed. Sufficient information, however, has been gained to 
justify the proposition of provisional size-limits, which will be useful 
in considering the statistics given below (p. 81) as to the destruc- 
