of the Fishery Board for Scotland. 
367 
brings from 6s. to 10s. the 200; it is still in good condition in February 
and March, and brings then 3 to 5 shillings the 200. In April, when 
immense shoals begin to arrive, the value goes down very fast ; and ships 
are finally loaded with them for a few shillings, and they are taken to poor 
sandy soils, there to serve as manure for cauliflowers or other vegetables. 
Of late years in the Zuider-Zee a good catch of herring had become an 
exception ; the autumn herring had nearly quite disappeared,* and the 
spring herring only entered in great numbers in the latter part of the 
season, when the fish was worthless, partly in consequence of its condition, 
partly because then the fasting of the Roman Catholics ceased and the 
demand for smoked herring only is important during that period. 
The principal question to be decided by scientific investigation was, 
whether the fishing with 'kuil '-nets in the Zuider-Zee might have exercised 
an injurious influence on the herring production of that sea. Now it was 
well-known that a small herring-like fish, called ' bliek ' by the fishermen, 
was caught in immense quantities with these nets. It always forms the 
main part of the masses of immature fish, the so-called ' nest,' which are sold 
as food for ducks or as manure. ' Though these small fishes from about 
8-12 centimetres in length had never been observed with their reproductive 
organs developed, those fishermen who inhabit the village oi ! Vollendam, 
at the west coast of the Zuider-Zee, and who were accustomed to fishing 
with the ' wonder '-kuils always asserted that it was a distinct species of 
fish and that it had nothing to do with the herring. This assertion, of 
course, was hotly contradicted by the fishermen of the south coast, who 
did not so much practice the ' kuil-net ' fishing. As the prosperity of the 
latter during the winter months always depends entirely on a successful 
herring fishing, while many of the fishermen from Volendam, accustomed 
to 'nest' fishing in the summer months, in winter time fish in the 
North Sea for plaice, cod, haddock, &c, it need hardly be said that a solu- 
tion of the problem, whether the so-called 'zeebliek' was young Zuider-Zee 
herring or not, was a matter of high importance for the regulation of 
the Zuider-Zee fishing. 
Dr Hoek's investigations cleared up this question. In the first 
place, he determined that the Zuider-Zee herring represents a distinct race 
of herrings, not quite identical with, but in most respects resembling 
the spring herring of the Baltic, so well-known to naturalists from the 
investigations of Dr Heincke of Oldenburg. In the next place, it was 
ascertained that this herring enters the Zuider-Zee for the purpose of spawn- 
ing there, that it spawns in May in those parts of the Zuider-Zee where the 
water is nearly fresh, that its larvae are a great deal smaller than are those 
of the herring of the open North Sea ; that the young herring stays in the 
Zuider-Zee till it is 10 or 12 centimetres long and returns from the open sea 
either (1) as a half -grown herring of about 16 centimetres in length in that 
condition erroneously called sprat by the fishermen, or (2) as a full grown 
herring approaching maturity, or nearly or quite ripe, of a length of 20 to 
25 centimetres. Through Dr Hoek's investigations it is made evident that 
the young herrings, which are killed in immense quantities by the kuil-nets, 
and the full-grown herrings which form the most important part of the 
fishing during the winter, are one and the same species, only differing in 
age. It was proved by these researches that the supposition on which 
the existing law rested prohibiting the fishing with ' Wonderkuilen 
during nine months of the year, was right. For various reasons, however, 
Dr Hoek did not decide on advising the Dutch government to extend the 
existing law. These reasons were, first, that this law permits the fishing 
* In the autumn of 1889, for the first time for several years, a considerable catch of 
herring took place. 
