216 NATURAL HISTORY OF AQUATIC ANIMALS. 



"From weighing and measuring known quantities it is found that one pound avoirdupois will 

 contain 190,000 of the smaller size, or that 1,000,000 eggs well drained will weigh about five 

 pounds. Again, by assuming one-nineteenth of an inch as the standard, or by precipitating a 

 known quantity in chromic acid and measuring, we find one quart, or fifty-seven and three-quarters 

 cubic inches, to contain a little less than 400,000, or that 1,000,000 will measure between two and 

 a half and three quarts. 



" With these facts in mind, it will be an easy matter to estimate the quantity of eggs taken 

 for hatching purposes during any given season. 



"When the little fish first breaks through the shell of the egg that confines it. the fetal curve 

 or crook is still quite noticeable, but it soon straightens, and is then about five-sixteenths of an 

 inch in length. At this time the yelk-sack, situated well forward, is quite large, but so transparent 

 as to escape the notice of the ordinary observer. This is gradually absorbed, disappearing wholly 

 in about ten to fifteen days, and the little fish begins to move about with a peculiar serpentine 

 motion, at times darting quite rapidly, and then remaining motionless, as if resting from its 

 exertions. It now begins its independent existence, and moves about more frequently, apparently 

 in search of food. From this date it is impossible to follow the Cod, for none have been confined, 

 and it is only by catching large numbers at different seasons and carefully recording their weights 

 and measurements that one is enabled to judge of their growth. The habits of the species, that 

 cause them to live near the shore for the first few years, furnish excellent opportunities for such 

 observations, and many were examined during our stay at Cape Ann. 



"At the outset the problem becomes difficult, in that the spawning period, instead of being 

 limited to a few weeks, as is the case with most species, extends over fully three-fourths of the year, 

 and the difficulty is greatly increased by other causes that affect the rate of growth of individuals 

 hatched at the same time. 



"The results were what might be expected; for a table of measurements, made late in June, 

 gave an almost continuous series, with only one or two breaks, that could with certainty be taken 

 to represent the non-spawning period of the fish. But though the gaps were so completely closed 

 by the extremes in variation, which seemed to cause even an overlapping, showing the last hatched 

 of one season to be smaller than the first hatched of the next succeeding, yet there was a tendency for 

 the greater number of individuals to be thrown into groups at intervals in the series, these seeming 

 to represent the height of the spawning season for the different years. The break was distinct 

 between the smallest and those of a year earlier, so that, taking the height of the spawning season 

 on the south side of Cape Ann to be December, the large number of young fry ranging from one 

 and a half to three inches must have been hatched the previous winter, and were consequently 

 about six months old. The large number of individuals having a length of nine to thirteen inches 

 indicated the normal growth of those hatched a year earlier, or fish of eighteen months, to be ten 

 to eleven inches, and their weight seven to eight ounces. The next group, or the fish thought to 

 be thirty months old, measured from seventeen to eighteen inches, with an average weight of two 

 to two and a quarter pounds. The fish now begin to increase more in weight than in length, soon 

 appearing in the markets as ' Scrod,' and by the following summer measure about twenty-two 

 inches and weigh from four to five pounds. 



"Beyond this period nothing can be determined, for the variation, constantly growing greater, 

 now gives every size and weight, with no indication of breaks in the series. 



"But enough has been learned, if the above be correct, to show that the male reaches maturity 

 at three and the female at four years; for the smallest ripe male noticed during the season of 

 1878-'79 weighed three and a half and the smallest ripe female five pounds. 



