714 EEPOKT OF COMMISSIONER OF FISH AND FISHERIES. 



montlis ill the same locality, a period far exceeding that required by any 

 other species of ^rhich we have any knowledge. 



This fact can be more easily understood when we remember that the 

 individuals do not deposit all their eggs in a single day or week, but 

 probably continue the operation of spawning over fully two months. 



That this is true there can be little doubt, for when the females first 

 begin to throw their eggs only a very small percentage of the whole 

 number are ripe, while the balance show every gradation to the perfectly 

 gTeen and immature. By frequent examination of individuals in more 

 advanced stages, it is found that the eggs gradually continue to increase 

 in size as they mature, and that as fast as they become detached from 

 the membrane they i)ass down through the channels to the opening, and 

 are excluded from the body, either by the will of the parent or by in- 

 ternal pressure caused by the increasing size of the eggs, to make room 

 for others. It would be impossible for a fish to retain all or even a small 

 part of its eggs in the roe-bags until the last had matured, for the in- 

 crease during the development is very great, and the eggs would come 

 to have a bulk greater than the entire stomach cavity of the fish. The 

 products of the ovaries of a 75-pound fish, after imj^regnation, would 

 weigh about 45 pounds and measui'e nearly 7 gallons, equal to over half 

 of either the weight or bulk of the fish. 



Another proof that the cod-fish deposits its eggs gradually during a 

 long period is seen in the fact that few can be taken fi'om the fish at any 

 one time. In '• stripping the fish," at the hatchery iii Gloucester, it was 

 found that only one quart, or less than 400,000 eggs, could be taken 

 from a 21-pound fish in a single day. Allowing the ovaries of this fish 

 to contain 2,700,000 eggs, and the time of spawning to be two months, 

 the fish must deposit in the natural way 337,500, or nearly a quart, each 

 week. 



But by the artificial method, where strong external pressure is applied, 

 many more eggs are probably secured at once than would be naturally 

 thrown by the fish. Thus the fish must either gradually deposit more or 

 less eggs each day, during the entire spawning season, or it must deposit 

 at intervals separated by only a day or two at most. 



The schools move about but little diuing the spawning season, except 

 when driven away by enemies or by violent storms. After they reach 

 the waters of Cape Ann, fishing continues best in the same localities and 

 even upon the same spots until they leave. The individuals, too, seem 

 to move about but little among themselves. When the female becomes 

 rix)e she remains quietly near the bottom, while the male, a little more 

 active, often swims higher up. This is indicated by the fact that much 

 greater numbers of spawning females are taken with the trawl lying di- 

 rectly on the bottom than with the hand-line a httle way above it, while 

 the males are taken on one as readily as on the other. 



It may not be impossible that the eggs are fertilized while floating 

 about in the water some minutes after exclusion, and that the strong 



