SPAWNING HABITS OP THE COD. 217 



" Evidence is not wanting to show that a Cod spawns every year, aud that it deposits the 

 entire number of eggs in the ovaries each season. We have examined hundreds of specimens and 

 have failed to find a single instance where the condition of the ovaries did not clearly indicate 

 that such was the case. During the first of the season no mature fish were found in which 

 eggs were not present, though they often varied greatly in development from very small to 

 nearly ripe. Again, later in the season, no spent fish were seen with any eggs remaining 

 in the ovaries; and no fish were found during the spawning period in which the condition of the 

 ovaries did not indicate that the eggs were gradually maturing, and would be deposited before the 

 close of the season. 



"The eggs contained in the ovaries are separated into little irregular conical clusters, each 

 being connected with the general mass by a slender thread that expands into a delicate membrane 

 containing minute and diffusely branched blood-vessels. This membrane envelops each of the eggs, 

 and the blood-vessels supply the nutrition so necessary to their future growth and development. 

 As the eggs mature they gradually increase in size, until, when ripe, they become detached from 

 the membrane, and pass down through secondary channels into the main channel leading to the 

 genital opening of the female. 



"The first ripe female seen during the season of 1878-'79 was found in a lot of shore- 

 fish or ground-tenders landed September 2. The eggs were noticed to be running from this fish as 

 it lay upon the floor of the fish-house. On opening it, we found that it had just begun spawning, 

 for a few eggs only, perhaps five per cent, of the entire number, were transparent, and a small 

 number of these had separated from the membrane and fallen into the channels leading to the 

 genital opening, while the great bulk were far less mature and represented almost every stage of 

 development from green to ripe. 



"From this date ripe fish, both males and females, were occasionally taken, though they did 

 not become abundant until the middle of October. Early in November, when the school-fish made 

 their appearance on the south side of Cape Ann, the individuals varied greatly in their spawning 

 condition; some were quite ripe and had already thrown a portion of their eggs, while others were 

 so green as to indicate that they would not spawn for several months at least, though, in nearly 

 all, the eggs had begun to enlarge. By the first of December fully fifty per cent, of the catch had 

 commenced spawning, but when driven away, probably by the unusually heavy storms, in January, 

 a few were not quite ripe, and the majority had not thrown all their eggs. 



"About the first of February the fish in Ipswich Bay were found to average fully ninety per 

 cent, males, with the spermaries mostly well developed. At this time there was a great variation 

 in the ovaries of the females; of these not more than one in ten had spawned, while fully sixty 

 per cent, were still green. By the middle of the month the females numbered about forty per cent., 

 though over half had not commenced spawning. On March 13, three hundred fish from this school 

 were opened, with the following results: Fourteen per cent, were spent males; fifty -three per cent, 

 were ripe males; six per cent, were spent females; fourteen percent, were females in various stages 

 of spawning; aud eleven per cent, were green females. May 10, fully half of the females had not 

 finished spawning, and an occasional green one was noticed. Even in June, when the fish left the 

 coast, a very few, though ripe, had not finished throwing their eggs. 



"The results of the above observation prove not only interesting, but surprising, for we find 

 the Codfish spawning through nine consecutive months in the same locality, a period far exceeding 

 that required by any other species of which 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 



