BULLETIN OF THE UNITED STATES FISH COMMISSION. 195 



the stone, so as to form a slightly conical mass almost identical with a 

 cluster on one of the stones dredged at Ballantrae. As this little heap 

 of eggs increased — some falling to the left side one moment, while others 

 fell to the right the next, according to the currents in the water — the 

 males continued circling round her at various distances, while the other 

 females in the tank remained apart. The males remained from 8 to 10 

 inches above the bottom of the tank, and formed circles varying from 

 18 inches to 2 feet C inches in diameter. Some of the males were 

 swimming from right to left, others from left .to right, and although 

 there was no darting about, no struggling among themselves, there 

 was a peculiar jerking of the tail as they performed their revolutions. 

 Soon the object of this peculiar movement was suflBcieutly evident. 

 Three or four times during each revolution each fish expelled a small 

 white ribbon of milt, which varied from half an inch to three-quarters 

 of an inch in length, and was nearly a line in breadth across the center, 

 but pointed at both ends, and somewhat thinner than it was broad. 

 These delicate ribbons slowly fell through the water, sometimes reach- 

 ing the bottom almost undiminished in size, but in most instances they 

 had almost completely dispersed before the bottom was reached. In 

 this way the whole of the water about the female became of a very faint 

 milky color, and practically every drop of it was charged with sperms, 

 as was afterwards ascertained. It will thus be seen that there is no 

 attempt whatever on the part of the males to fertilize the eggs as they 

 escape from the female. While the female is depositing the eggs at the 

 bottom, the males concern themselves with fertilizing the water in the 

 neighborhood, and it will be observed that the males are careful to 

 guard against the influence of currents by forming circles around the 

 female and shedding milt on the way. It matters little how the cur- 

 rents are running, they are bound to carry some of the milt towards 

 the eggs, the milt, like the eggs, sinking though not adhering to the 

 bottom. 



This then is the natural process of depositing and fertilizing the ova 

 of the herring in comparatively still water. When the female had de- 

 posited a certain number of eggs at any given spot, she moved forward 

 in a somewhat jerky fashion without rising from the bottom, and as she 

 changed her position the males changed theirs, so that the female was 

 always surrounded by a fine rain of short sperm ribbons. A specimen 

 of Hydrallmannia sent from Eyemouth seems to indicate that the female 

 moves about among sea-firs and sea-weeds in exactly the same way 

 as she does among stones. On each stem of the colony there is a clus- 

 ter of ova about the size of a small grape, and all the clusters had reached 

 on arrival the same stage of development as if they had been deposited 

 about the same time and by the same fish. 



This method of depositing and fertilizing the eggs accounts, I think, 

 for all the eggs, or at least for a very large percentage of those found 

 attached to sea-firs, sea-weeds, and stones, containing developing em- 

 bryos. 



