57 



genital opeuiogs almost spontaneously. That day I found so many 

 ripe herriügs aniougst tbose caugbt with bow-nets in the neigh- 

 bourbood of Marken , tbat I resolved to try to collect (with the 

 aid of the dredge) such spawu as luight be deposited oü the bot- 

 tom. 1 was told tliat abuiidance of spawn might be found between 

 the island of Marken and the coast, near a point called the Volen- 

 dammer corner. I was uot suceessful tbat day and believed it 

 was due to the circumstance that the number of ripe male her- 

 rings was not yet very considerable. Numerous ripe male fishes 

 were observed for the first time on 25 April: wooden boxes con- 

 tainiug herriuc^s showed the fish floating in the soft roe. Eggs 

 were present also, and those I collected and investigated had all of 

 them been fertilized. On the 1*** May I searched again the bottom 

 at about the same place as on April 17. At this place the depth 

 was 4 feet; that day the temperature of the water was (at 3 

 o'clock in the afternoon) 12° C, and the areometer showed 1.0087 

 (a little over 1 "/g salt). The water was extremely clear. With the aid 

 of a little dredge a great quantity of spawn was collected at diffe- 

 rent points; it was found attached to various objects, such as little 

 stones, shells, pieces of wood etc. A comparison with such eggs 

 as were observed coming out of the female herrings made it quite 

 undoubted that these were indeed herring eggs. Moreover, whereas 

 immense quantities of herrings were taken at that place with the 

 aid of bow-nets on the very day that I collected the spawn , no 

 other fish was observed there at that time. 



In the beginning of May '88 bad weather during several days 

 made it quite impossible to continue these investigations. On 

 May 15 spawn was again collected: the eggs were now much 

 more advanced in development and contained an embryo curved 

 round the uutritive yolk. 



The deposition of the eggs of the herring, and probably also 

 their development in the spring of 88 were retarded considera- 

 bly by the cold and rough weather. Ou May 24 abundance of 

 eggs of tbis fish were still found in the neighboorhood of Urk 

 (to the south of the island). They were attached to various ob- 



