very young Cod and other Food-Fishes. 309 



alive longer tlian a month, when thej attained the length of 

 about 5 or 6 millim., though it is probable growth is some- 

 what slower in confinement than in freedom. It is clear at 

 any rate that a fish which is hatched devoid of a mouth and 

 circulation in April, and only a few milHm. in length, cannot 

 (so far as present observations lend support) grow to any 

 considerable size or attain great complexity of organization 

 that season. 



At sea the forms a little older than those seen in the labo- 

 ratory have generally escaped us, only a specimen or two 

 half an inch long having been captured in the tow-net ; yet 

 certain parts of the sea in May and June must abound with 

 the early stages of the cod. Of the later stages in every 

 variety there is no lack. Early in June, or, in some years, 

 in July, young cod appear off tlie rocks at St. Andrews in 

 shoals, their length varying from 1| in. to If in. A month 

 later they have attained If to 2^ in. They accompany the 

 green cod into the rock-pools, rich in tangles and other sea- 

 weeds, and which have a communication with the sea. They 

 feed there on the multitudes of larval crustaceans and Cope- 

 poda, and shelter themselves under the blades of the sea- 

 weeds when hunted. They are easily recognized by the 

 reddish colour of the occiput and gills ; and their coloration 

 (diced), large heads, lean bodies, and slower motion distin- 

 guish them from their associates, the young green cod, many 

 of which show a very distinct barbel on the chin, though it 

 is small in the adult. They go on growing as Sars indicates 

 and as mentioned in the ' Trawling Report.' 



To be brief, the main point of this note is the age of these 

 young cod which appear off St. Andrews rocks in June and 

 July. The spawning-season on the east coast of Scotland 

 (as ascertained both by examination and dissection of the 

 adults and capture of the eggs and embryos) is tolerably 

 uniform, and thus a fixed date is given for the reckoning. 

 According to Prof. Sars these would appear to be tiie young 

 of the season, and which next February would be a foot in 

 length. So far, however, as the growth of other fishes can 

 afford a means for comparison and judgment, it seems doubtful 

 if so rapid a growth can take place between April and June. 

 The condition of the vertebral column, skeleton in general, 

 and the structure of the otoliths [sagitta and asteriscus) in 

 the smallest of those which appeared this year on the 7th 

 June seem to me to point to their being the young of the 

 previous season, if the observations on the spawning-period 

 are correct, and indeed this would require to be much ante- 

 dated to tall in with the condition of the young cod as 



