BULLETIN OF THE UNITED STATES FISH COMMISSION. 193 



Vol. IV, ]Vo. 13. \^^ashiBij?toii, ». C. July 30, 1884. 



103.— OIV THE IVATlJKAIi AIVI> ARTIFICIAL FERTIJLIZATIOIV OF SEA 



IIEKRli\0 EOCiS.* 



By Prof. J. COSSAR ETVART, M, D. 



In 1862 Professor Huxley arrived at the conclusion that herring visit 

 our shores twice a year in order to spawn, some schools arriving during 

 the autumn, while others make their appearance during the winter. 

 The herring which spawn during the autumn chiefly frequent banks on 

 the east coast, while those which spawn during winter are most abun- 

 dant on the west coast. A report of the Scottish Fishery Board refer- 

 ring to the east coast spawning- beds was published in Nature on Novem- 

 ber 29 last. The present paper deals chiefly with the Ballantrae spawn- 

 ing-bed, which lies off the coast of Ayrshire. 



In 1862 Professor Allmau made some investigations for the Scottish 

 Fishery Board, and succeeded in dredging and hatching what was con- 

 sidered herring ova ; but since then, although important results have 

 been obtained by the German and American Commissioners of Fisher- 

 ies, little or nothing has been done in this country. 



When examining the Ballantrae bank the author of this paper suc- 

 ceeded in dredging several specimens of herring ova attached to stones, 

 sea-weed, and sea-firs. These stones coated with eggs varied from 6 

 inches to IJ inches in length, and from 4 inches to 1 inch in breadth, 

 but in all cases the eggs were attached to a comi^aratively smooth sur- 

 face, and they were arranged either in low cones or in comparatively 

 thin layers one or two eggs deep. The eggs on the sea-firs were always at- 

 tached in small clusters about half an inch in diameter around the stems. 

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

 various stages of development were at once visible, some of them appar- 

 ently 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 taken to the University at Edin- 

 burgh, where the eggs hatched on March 15, eight days after their re- 

 moval from the spawning-ground, and to-day (March 17) they are three- 

 eighths of an inch in length, extremely active, and swimming freely 



about in the water. 

 By taking soundings over the Ballantrae bank in various directions 



it was ascertained that it consisted of rock, stones, shells, and coarse 



sand, and that the depths varied from 7 to 13 fathoms. The outer edge 



of the bank shelved at most points rapidly until a depth of 17 fathoms 



'Abstract of a paper read at the Royal Society, March 27, and published in Nature, 

 April 3, 1884. 



Bull. U. S. F. C, 84 13 



