of the Fishery Board for Scotland. 



101 



the water was too shallow to permit the large boats to drift. They were also 

 being taken in nets anchored in three fathoms of water. When the herrings 

 are so ripe that the eggs and milt run freely from them they are termed 

 locally " maisie herrings." 



With the courteous assistance of Mr. W. Keir, Fishery Officer, Anstruther, 

 arrangements were made whereby the skippers* of certain boats kindly 

 agreed to try to bring a few herrings ashore alive. For this purpose herring 

 barrels were employed. A small hole was bored in the side of the barrel 

 near the bottom ; it was closed with a peg, and was intended as an outlet for 

 the bottom water when the water was being freshened. Some live ripe 

 herrings were got in this way, and from them I obtained a sufficient supply 

 of spawn. Spawn was also taken from some dead herrings. 



The method in which the artificial fertilization was carried out was that 

 described by Ewart.t The milt was pressed out into the water in a tub. A 

 female herring was then taken into the tub. A glass plate, 9 inches square, 

 was held below the fish to receive the eggs as they were pressed out in a 

 narrow ribbon. The ova were distributed as well as possible over the plate, 

 although the struggles of the fish interfered to prevent this being always 

 satisfactorily accomplished, the movements of the tail occasionally scattering 

 the eggs. The eggs adhered to the plate immediately on contact, There 

 were often some scales attached to the eggs. Where the eggs were taken 

 from fishes that had been several hours dead the plates were more liberally 

 sprinkled with scales than in those cases where the fishes were alive. 



The number of herrings brought back in the barrel was usually about ten, 

 and as a rule the majority were dead on the arrival of the boat ; they had 

 been from six to eight hours in the barrel. It was found that the herrings 

 which survived were ripe, those in which the ova and milt ran out on gentle 

 pressure. The females having large hard roes succumbed more readily. 



The glass plates with the ova- adhering to them were allowed to stand for 

 from one to seven hours in the tub among the water containing the milt. 

 They were contained in wooden cases, each of which held six or more plates. 

 For transport to Aberdeen the cases were put into barrels filled with sea 

 water. The cases floated. The barrel was headed up after being filled 

 completely. 



There was a certain amount of doubt as to how long it was safe to leave 

 the eggs in the tub in which there was an excess of milt. It is probable that 

 fertilization is completed in a comparatively short time, e.g., within three or 

 four hours. Brook noted the evidence of fertilization in the formation of 

 the perivitelline space in one case half an hour after the mixing of the sperm 

 and ova. Probably the only danger which might be expected to threaten 

 the eggs would be from the decay of the unused milt. At this time the 

 weather was very cold, and it is probable the danger was not a very near one. 



Six lots of spawn were got in all, viz. : — 



I. The first lot of spawn was obtained on the morning of 18th February. 

 The herrings were dead, but they had been alive just a short time previously. 

 The milt flowed out freely on pressure in a rather coherent form. The eggs 

 were fertilized at 2 a.m., and the plates were left in the tub till 10 a.m. 

 They were then transferred to the barrel and sent to Aberdeen. They were 

 unpacked at the Laboratory and put into ruuning water at 7 p.m. They had 

 been nine hours in the barrel. 



II. The eggs of this lot were obtained on the afternoon of ^February 18 

 from both live and dead herrings ; the milt was supplied by live r males. 

 The plates stood in the original water in which the eggs and milt were 



* Messrs. M'Kay, T. and J. Birrel, Anstruther ; J. Paton, Montrose ; and Smith, 

 St. Monance. 



tEwart — "Natural History of the Herring." Second Annual Report of the 

 Fishery Board for Scotland for 1883. Edinburgh, 1884. P. 71. 



