77 



For the Zuiderzee the sprat is a fish of no consequence. I thought 

 however, that it was important to insert here the formulae I cal- 

 culated, as comparison with those of the herring shows in a re- 

 markable way the great merit of Heiucke's method. 



Anchovy. On this fish of late very important investigatious 

 have been carried out, and their results published by Hofimann , 

 Wenekebach and others. I have not been able to add a great 

 deal to our knowledge about this interesting fish ; I only was 

 fortunate enough to coUect some information with regard to 

 the time when most eggs of this fish are found floating in the 

 Zuiderzee. Whenever I used the surface-uet duriug the summer 

 of '88 I paid special attention to this question. Yet I only twice 

 had the good luck to observe these eggs: on June 7 aud again 

 on June 14. Though the fishing with surface-nets was continued 

 until the middle of July , after June 14 no eggs of anchovies 

 were met with. Various circumstances may have occasioned 

 this, and probably the principal cause was that I was obliged 

 to use the pelagic net at places in the Zuiderzee where the 

 salinity of the water was particularly small , and the auchovy 

 not prefers such water. Weber and Wenekebach during their 

 investigations of '86 collected most eggs between 6 and 7 July — 

 this happened , however , in the northern part of the Zuiderzee 

 on the other side of the line running from Enkhuizen to Sta- 

 voren. These were no doubt eggs of fishes which entered the 



