34 EEPRODUCTION AND DEVELOPMENT OF TELEOSTEAN FISHES ' 



is only a single one present. Bat so far as I am aware, attention 

 lias not liitlierto been called to the peculiar position of this pigment 

 on the deeper side of the oil-globule, though it probably has the 

 same relative position in other species. 



Historical and Comparative. — Some valuable information and 

 deductions concerning the life-history of the mackerel are contained 

 in a report made by Prof. Gr. 0. Sars to the Department of the 

 Interior of the Norwegian Government. Prof. Sars carried on 

 investigations of the Norwegian fisheries for a series of years from 

 1864 to 1878, at the request of the Grovernment, and his reports 

 have been officially published from time to time at Christiania. The 

 whole series was finally published in one volume in 1879. But to 

 the English reader they are more easily available in the translations 

 published in the Report of the United States Commissioner of Fish 

 and Fisheries for 1877. In the report of Prof. Sars for 1875 he 

 states that he made some preliminary investigations of the spawning 

 of the mackerel during a zoological tour in the summer of 1865. 

 He says that this fish spawns at the surface of the water, near or far 

 from the coast, and that the roe floats near the surface and there 

 goes through all the stages of its development ; that the spawning 

 period is as a general rule the first half of July ; that the ova when 

 shed are small beads as clear as crystal, which float near the surface 

 as long as they are alive ; that the ova are of about the same size 

 as those of the cod or a little larger, but are distinguished from 

 these by a large and very distinct and clear oil -bladder near the 

 upper pole ; that he obtained the fertilized ova from the sea by 

 means of a fine net, and was able to keep these during development 

 until they hatched. He believes that by the end of one year the 

 young fish are about as long as the finger, that in two years they 

 grow to the size of a common herring, and at the end of three years 

 are full-grown and spawn themselves ; that during the first two years 

 they remain near shore, roaming about in the open water. 



With regard to the habitat, the home of the mackerel. Prof. 

 Sars, rightly no doubt, considers that it extends in the eastern 

 part of the North Atlantic along the whole western coast of Europe 

 from the Orkney Islands and the north coast of Scotland to the 

 Metiterranean and southward to the Canary Islands. It occurs on the 

 southern and western coasts of Norway, on all the other coasts of 

 the North Sea, on the western coast of Great Britain, round Ireland, 

 in the Channel, on the coasts of France, Spain, and Portugal, and 

 in the Mediterranean as far as the Black Sea. It also occurs on the 

 Atlantic Coast of North America from Labrador to Cape Hatteras 

 (see : Materials for a History of the Mackerel Fishery, U.S. Fish. 

 Comm. Report for 1881). Prof. Sars rightly condemns the 



