300 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



locality at Salvoe and Tvilanparhohnerne, on the. west side of the island 

 of Karmoe. I found, however, that in view of the investigations to be 

 made, it would be of special interest to have these basins stocked with 

 live spring herring, so as to be able to follow the development of the 

 sexual orgaus until the following year, and, if possible, to throw some 

 more light on the nature and development of the so-called " blood-her- 

 ring." For this purpose each of the basins was stocked with 500 her- 

 ring; and among those in the Tvilanpar basin there were some "blood- 

 herring." In one of the walls of the Tvilanpar basin I had an iron 

 grating inserted, so that constant connection with the sea was main- 

 tained and the herriug were prevented from slipping out. - To furnish 

 the herring in this basin with food I placed in it a large number of lob 

 sters with roe, so that the newly-hatched young lobsters might supply 

 food for the herring during summer. In the Salvoe basin the conditions 

 were such as to make it unnecessary to have special connection with 

 the sea, as there is a regular connection at every tide, which, however, 

 does not cause the water to rise so high ihat the herring could slip out. 



During the course of spring and summer I had many opportunities 

 for observing the herring. In April they were lean, and looked in every 

 respect as if they had been starved. In May they had recovered some- 

 what, and in June they had become so fat that the common people 

 called them "pretty" herring. But the circumstance which was of the 

 greatest interest to me was that on June 20 I found among 10 herring 

 taken from the Tvilanpar basin 2 (a male and a female) full of milt 

 and spawn and almost ready to spawn. It would, of course, be some- 

 what premature to base on this single instance a theory as to the de- 

 velopment of the so called " blood-herring;" but the fact is neverthe- 

 less one of great interest, and 1 deem it proper to make it known. I 

 cannot force myself to believe that these two specimens should beloug 

 to the spring herring ; but I am rather inclined to the opinion that they 

 belong to the "blood-herring;" and the conclusion which might naturally 

 be drawn therefrom would be that the " blood-herring" beloug to those 

 herring which spawn in summer and autumn, which are found in the 

 shallow portions of the North Sea, and which during July and August 

 are, in enormous numbers, caught by the Dutch and Scotch fishermen. 



I am convinced that if the investigations relative to herring are to 

 lead to any practical result they should not be made in winter alone ; 

 but that the places where the spring herring stay during summer 

 should be sought, and that the winter investigations should be contin- 

 ued during summer and autumn between Norway, the Shetland Islands, 

 and Iceland. For several years 1 have endeavored to establish seine 

 fisheries on a rational basis iu the North Sea, and thus to provide a new 

 souree of income for our coast population. I am of opinion that such 

 summer and autumn seine fisheries would be the first practical result 

 of the investigations referred to above, while at the same time our 

 knowledge of the natural history of the herring would be considerably 

 increased. 



