444 THE POPULAR SCIENCE MONTHLY, 



be concluded that they are the progeny of herrings which spawned 

 early in the year, in the neighborhood of the estuary of the Thames, 

 up which these dainty little fish have wandered. Whether it is the 

 general habit of young herring, even of those which are spawned in 

 deep water, to migrate into the shallow parts of the sea, or even into 

 completely fresh waters, when such are accessible, is unknown. 



In the " Report on Trawling " (1863) we observe : 



" It is extremely difficult to obtain any satisfactory evidence as to 

 the length of time which the herring requires to pass from the embry- 

 onic to the adult or fall condition. Of the fishermen who gave any 

 opinion on this subject, some considered that a herring takes three, 

 and others that it requires seven years to attain the full or spawning 

 condition ; others frankly admitted that they knew nothing about the 

 matter ; and it was not difficult, by a little cross-examination, to satisfy 

 ourselves that they were all really in this condition, however strongly 

 they might hold by their triennial or septennial theories. Mr. Yarrell 

 and Mr. Mitchell suppose with more reason that herring attain to full 

 size and maturity in about eighteen months. 



"It does not appear, however, that there is any good evidence 

 against the supposition that the herring reaches its spawning condition 

 in one year. There is much reason to believe that the eggs are hatched 

 in, at most, from two to three weeks after deposition, and that in six 

 to seven weeks more (that is at most ten weeks from the time of lay- 

 ing the eggs) the young have attained three inches in length. Now, it 

 has been ascertained that a young smolt may leave a river and return 

 to it again in a couple of months increased in bulk eight or ten fold, 

 and, as a herring lives on very much the same food as a smolt, it ap- 

 pears possible that it should increase in the same rapid ratio. Under 

 these circumstances nine months would be ample time for it to enlarge 

 from three to ten or eleven inches in length. It may be fairly argued, 

 however, that it is not very safe to reason analogically from the rate 

 of growth of one species of fish to that of another ; and it may be well 

 to leave the question whether the herring attains its maturity in twelve, 

 fifteen, or sixteen months open, in the tolerably firm assurance that the 

 period last named is the maximum." 



On comparing these conclusions with the results of the careful ob- 

 servations of the Baltic Commissioners, it appears that we somewhat 

 over-estimated the rate of growth of the young herring, and that the 

 view taken by Yarrell and Mitchell is more nearly correct. For, sup- 

 posing that the rate of growth after six months continues the same as 

 before, a herring twelve months old will be nearly six inches long, and 

 at eighteen months eight or nine inches. But full herrings may be 

 met with little more than seven inches long, and they are very com- 

 monly found not more than nine inches in length.* 



* Ljungman (" Preliminary Tleport on Herrings and Herring Fisheries on the West 

 Coast of Sweden," translated in United States Commission Report, 1873-'75) speaks of 



