1884.] Artificial Fertilisation of Herring Ova. 



453 



The cod-hook grapnels brought up the trammel-nets (in which were 

 a few recently caught herring and a large number of fish, chiefly 

 herring, in an advanced stage of decomposition), and also most of the 

 sea- weed ; the oyster-dredge brought up all the stones coated with 

 spawn. These stones varied from 6 inches to \\ inches in length, 

 and from 4 inches to 1 inch in breadth, but in all cases the eggs were 

 attached to a comparatively smooth surface (which probably was 

 uppermost when the eggs were deposited), and they were arranged 

 either in low cones or in comparatively thin layers, one or two eggs 

 deep. 



The eggs on the laminaria and other sea-weeds were either lying 

 separately or in small isolated groups, or embedded amongst the 

 roots, while those on the sea-firs were always attached in small 

 clusters about half an inch in diameter around the stems. 



On the trammel-nets the eggs were scattered in an irregular manner 

 over several square feet. They were always most abundant near the 

 fish from which they had escaped, and tailed away sometimes to the 

 right and sometimes to the left, the position having undoubtedly 

 been determined by the direction of the currents at the moment they 

 escaped. 



On examining the spawn found on the stones and sea-weed, 

 embryos at various stages of development were at once visible, some 

 of them apparently only three days old, while others had distinct 

 eyes, and from their violent movements and their size seemed almost 

 ready for hatching. Some of the egg- coated stones were preserved in 

 spirit, others were deposited in the Rothesay Aquarium or retained 

 on board the " Jackal," while others were conveyed to the University 

 of Edinburgh. I have not heard what has happened to those left at 

 Rothesay, but those left on the "Jackal" under the care of 

 Lieutenant Prickett, hatched on the 13th, five days after they were 

 dredged ; and those carried off to Edinburgh (notwithstanding that 

 their small supply of water was neither changed nor aerated for 

 nearly twenty hours), hatched on the 15th March, eight days after 

 their removal from the Ballantrae Bank, and to-day (17th March), 

 the fry are three-eighths of an inch in length, extremely active, and 

 swimming freely about in the water. 



All the eggs on the trammel-nets and on the floats in connexion 

 with the nets were dead ; they looked as if they had never been 

 fertilised, while some of those scattered over the smooth surface of 

 the stones attached to the lower margin of the nets contained living 

 embryos. 



In addition to the stones, sea-weeds, and trammel-nets, the dredges 

 brought up amongst other things numerous shells of Pecten, 

 Buccinum, and Cardium, small specimens of Chiton, and the eggs of 

 several nudibranchs attached to stones ; several Echinoderms — 



2 I 2 



