398 THE ZOOLOGIST. 



fine pigmentation appears, and shortly afterwards the silvery hue 

 commences — the Whitebait stage. 



Mcintosh and Masterman thus summarize the early Herring : 

 — M The young larva, hatched at from 5 mm. to 7 mm. in length, 

 lives near the bottom till about 10 mm. is attained by a rapid 

 increase in length. The attenuated post-larval Herring then 

 migrates upwards through the mid-water to the surface, the mid- 

 water stage lasting from about 10 mm. to 23-24 mm., and the 

 surface stage from 24 mm. to 27-28 mm. [roundly speaking, 

 one inch or thereabouts], when a movement shorewards takes 

 place, and the littoral habit is acquired." 



Their further increment and subsequent erratic movements 

 are a more tangled skein to unravel. Growth and maturation 

 are complicated and confused by a double spawning period. 

 Data give a length of three inches the first twelvemonth, to five 

 inches the second year, and to eight or nine inches the third 

 year, when sexual maturity is attained ; but British and foreign 

 observers are not quite in unanimity thereon. It would appear 

 though that in the case of the Baltic as well as British Herring 

 there are two marked spawning seasons, the so-called winter and 

 summer Herrings. The same Herrings, however, do not spawn 

 twice annually, the summer and winter stock being races apart, 

 whose spawning localities essentially differ. Winter spawners 

 frequent inshore brackish waters, whereas summer spawners are 

 more strictly sea-dwellers, coming near the coast, but not into 

 estuaries at spawning season. The Clyde, Forth, and Plymouth 

 Herring are winter, the North Sea group summer breeders. The 

 former estuarine fish come and go within a limited area, the 

 latter offshore have a wider sea migration. In both cases, 

 though, it is a see-saw towards and away from the coast, the 

 so-called summer Herring spawning in deeper water further 

 distant from land. 



The supposed mystery of the fish returning to their own 

 special grounds, Cunningham thinks is due to their habit of 

 herding in shoals. Temperature and food drive the fry up an 

 estuary, and there as they grow, meeting older brethren, associate 

 and accompany them back to the sea-spawning ground. 



Of other Clupeoids, it is singular that the Sprat is much more 

 used as an article of diet in England than in Scotland, though to 



