BATE OF GROWTH OF SOME SEA. FISHES. 259 



or the temporary finer rays still remain. Tlie figure shows the speci- 

 men in a somewhat shrunken condition. The stage of this specimen 

 is somewhat earlier than that of the pilchard larva figured by me 

 in Plate X, vol. ii, Part 2 of this Journal. This anchovy larva 

 must have been not more than one month old, having been hatched 

 in June. On September 19th Hoek obtained some small anchovies 

 measuring 6*2 to 8*5 cm., and estimates their age at two and a 

 half to three months, an age at which the herring measures 4"5 

 to 5*0 cm. 



Hoffmann has also described specimens believed by him to be 

 larvae of the anchovy.* His identification was based on the fact 

 that the number of the vertebrae was forty -eight. Giinther gives 

 the vertebrae in the sprat as forty-seven to forty -nine. Mobius and 

 Heincke forty-six to fifty ; the latter authors give the number in the 

 anchovy as forty-six to forty-eight. Matthews found the number 

 in the sprat to be forty-eight. But Hoffmann says he found always 

 forty-nine to fifty vertebrae in the sprat in the Zuyder Zee, and 

 forty-eight in the anchovy. The clupeoid larvae he took were 

 captured on July 27th to 31st, and varied in length from 16 to 30 mm. 

 The smaller of these might easily have been anchovies hatched in 

 June ; that the largest were anchovies in much more doubtful ; but 

 even if they were, it would by no means prove that young anchovies 

 hatched in June could reach a length of 8*0 cm. in August. 



Reference has previously been made in this Journalf to Hoffmann's 

 theory concerning the relation between the summer temperature of 

 the air in the region of the Zuyder Zee and the variations in the 

 annual catch of anchovies from that body of water. The theory 

 is that an unusually warm summer in one year is followed by an 

 unusually large catch of anchovies in the following year. The 

 explanation of the supposed sequence is that the warm summer 

 means a very abundant production of eggs and young larvae of the 

 anchovy ; the high temperature ensures an abundance of food for the 

 young fish, and also favours their healthy development and growth. 

 The young thus survive in unusual abundance, to depart for the open 

 sea in autumn and return in the following summer, and give rise to 

 a successful fishery. It may be suspected that the theory itself 

 owed its origin partly to Hoffmanu^s mistaken belief that the anchovy 

 reached its adult size and condition in one year. That belief having 

 been proved to be unfounded, some other explanation of the con- 

 nection between summer temperature and fishery must be sought, 

 supposing the connection really to exist. Ehrenbauna remarks that 

 the theory is equally consistent with his own view that the young 



* Verslag Nederlandscbe Zeevisschereien over 1886, Bijlage iv. 

 t Vol. i, N. S., p. 334. 



