73 



herrings of the Northsea-type among those caught in spring. Eight 



herrings remain , eacli of tliem represented only once; these are: 



2b üB 

 3 b IIA 

 3 c II A 

 2c IA 

 2c OB 

 2 b IliC 

 3b IC 

 3a Ui 



I thiuk it hardly necessary to poiut out the great reserablauce 

 of each of these formulae in most respects to those enlisted ia 

 the table given above : 2 b O B and 2 c O B are nearly identical 

 with 2 b 1 B and 2 c I B ; 3 b II A and 3 c II A much resemble 

 3 b II B and 3 c II B ; 2 c I A corresponds with 2 c I B ; 2 b 

 III C with 2 b II C, and 3 b IC with 3 b II C; 3 a IB is the only 

 formula which does not correspond as far as the first two characters 

 are concerned with one of the formuUie of the table. Altogether 

 there are only 18 of the 120 autumn herrings investigated, which 

 do not show the type of the true Zuiderzee-spring-herrings ; 85"|o 

 of them , however, show this type most decidedly ; whence for 

 me there remains not the least doubt, that (generally speaking) 

 all the herrings which visit the Zuiderzee belong to one race only , 

 which is a race of herrings spawning in the spring-raonths in 

 brackish water. 



I calculated the formulae for a number of small (not full-grown) 

 herrings of the Zuiderzee (so-called zeebliekjes) also. As I had 

 seen already a good deal of the life-history of the Zuiderzee- 

 herring before, and had been present, so to say , when the young ones 

 were born , and had observed them during their early youth and 

 more or less regular growth , I did not feel the slightest doubt 

 with regard to their descent. It was not exactly on account of this 

 that I wished to compare their formulae with those of the full- 

 grown herrings: my intention in doing so was rather to have 

 another occasion for testing the method I had hitherto foliowed. 



I investigated 100 small fishes, the length of which as a rule 

 varied betweeu 50 and 100 mm., a few however were smaller 



