224 BATE OF GROWTH OF SOME SEA FISHES. 



years, and there is iio evidence in his experiment that any 

 specimens spawned at two years of age. In fact, his experiment 

 was made merely with the object of proving that artificially hatched 

 larvae could grow into adult fish, and he seems to have paid little 

 attention to questions as to the size or age at which sexual maturity 

 is attained. It seems to me probable that, either by reason of the 

 confinement or of insufficient food, the size reached by Dannevig's 

 specimens in two a half years was considerably below the normal 

 size of free individuals of that age. 



Dannevig mentions in his Report for 1886 that on the 13th May 

 he placed 5000 newly hatched flounders in the pond or reservoir 

 above mentioned with the young cod ; in the translation given by 

 Prof. Ewart, loc. cit., the species is erroneously given as Pleiiro- 

 nectes limanda, but Dannevig himself states that skrtthbe, the word 

 he uses, means PL Jlesus. In May, 1888, these flounders had 

 attained a length of 7 or 8 inches, so that some of my captive 

 flounders, described m the following section, though reared in 

 comparatively small tanks, were larger than those kept by Dannevig 

 in a large open-air reservoir. Dannevig" says nothing about the 

 spawning of these captive flounders. 



Ewart states that Dannevig reared herring in the same reservoir, 

 but I can find no reference to herring in the reports of the latter, 



Pleuronectes Jlesus, the Flounder. 



The specimens of this species reared in the aquarium, whose 

 length in the spring of last year was given in my previous paper, 

 were measured again this year when they were about two years old. 

 Their lengths and conditions were as follows : 



February 23rd, 1892. Specimens in a table tank 5 feet by 2^ 

 feet in area, by 1 foot 5 inches deep, measured and examined. 

 Total number of specimens 24. 



Of these three were ripe males, and one was a female, which 

 though not actually ripe had a well-developed ovary, which would 

 without doubt yield ripe ova this season. The lengths of these 

 were — 



Males. Female. 



23-3 cm., 9-2 in. ... 21-3 cm., 8-4 in. 



22-2 „ 8-8 „ 

 21-0 „ 8-3 „ 



The remaining specimens were all unripe ; their sexes were not 

 determined. Their lengths were — 



