40 REPEODUOTION AND DEVELOPMENT OF TELEOSTEAN EISHES 



comparison. Lately, in 1887,* Henseu has stated that he obtained 

 ova taken from the sprat and artificially fertilized, and found they 

 agreed in all respects, both in size and sti'ucture, with the ova 

 he got in the tow-net. There can be little doubt that my ova from 

 the Firth of Forth were of the same species as Hensen's ; my 

 measurement of the ovum was somewhat smaller than his, but the 

 length of the larva was almost exactly the same in the two cases. 

 And it is also pretty certain that Agassiz' ovum found off the 

 American coast belonged to some species of Clupea. 



With regard to Clupea pilchardiis, Couch long ago in 1865, in his 

 Fishes of the British Islands, stated that the pilchard spawned at 

 the surface o£ the sea. His account is as follows : '' In April and 

 May they are habitually prepared to shed their spawn, which they 

 now do at a further distance from land and over deeper water than 

 is the case at the warmer season of autumn, when again, early or 

 later, they perform the same function, although we do not feel 

 assured that they are the same fishes which thus perform the duty 

 of procreation on both occasions.'^ " I have reason to suppose that 

 the spawn is shed at the surface, and mingled with it a large 

 quantity of tenacious mucus in which it is kept floating while it is 

 obtaining the vivifying influence of the light and warmth of the 

 sun. My notes on this subject are that presently, after spawning, 

 a sheet of jelly, enclosing myriads of enlarging grains of spawn, has 

 been seen to extend several miles in length, and a mile or more in 

 breadth over the surface of the sea.^' We shall see how far Couch 

 was from a knowledge of the real spawn of the pilchard. 



In a Report by Frank Buckland and Spencer Walpole, Commis- 

 sioners for Sea-Fisheries, on the sea-fisheries of England and Wales, 

 presented to Parliament and oflacially published in 1879, evidence 

 concerning the spawning of the pilchard, given by Mr. Dunn, of 

 Mevagissey, is recorded. In Appendix No. Ill to that Report, 

 by Frank Buckland, the following quotation is given from a letter 

 from Mr. Dunn : "On the 28th of May, 1871, I took a pilchard 

 alive, and in the act of spawning, about twenty miles from land. 

 With the help of my hands the fish deposited the remaining spawn 

 into a bucket of sea-water. Immediately the spawn rose to the 

 surface of the water with the buoyancy of cork, and instantly the 

 eggs separated from each other. By the candle-light the globules 

 appeared bright and almost transparent. After a few minutes they 

 lost their buoyancy save just dipping under the surface, others 

 floating an inch or two further down. In this state they continued 

 for two hours, then a white speck showed itself in each globule, 



* Fiinfter Bericbt der Comni. Uuters. deutschen Meere, Beilin, 1887. 



