CLUPEID^E. 217 



25th, 1882), remarked from Plymouth that the herrings have not yet left the 

 coast, and many among them have not yet spawned. It is evident that off Great 

 Britain there are two chief periods for spawning, but that at various places some 

 spawning fish may be captured at any month throughout the year. The autumn 

 breeding time would appear to be the most extensive. 



The number of eggs which have been found in a single herring has varied 

 from ten to thirty thousand, when shed it sinks to the bottom of the sea, while 

 along with it is a glairy fluid which enables the ova to adhere to any object with 

 which it may come in contact. Ropes or nets drawn through herring spawn 

 become thickly coated with it, and large quantities are brought on to the decks of 

 fishing boats. Nets set in water where spawn exists in a very short time become 

 heated similarly to what occurs when heavy catches of fish have been made. The 

 locality selected is often over rough ground, while sea-weed may be found covered 

 with this adhering spawn. In the Baltic and localities where the water is brackish 

 and almost fresh they have been observed to select two or three feet of water for this 

 purpose. It seems highly probable that they deposit their spawn wherever they 

 happen to be, as herrings in which this was exuding were taken at least forty 

 miles out at sea, or in forty to fifty fathoms of water, while it is very attractive to 

 other fish especially cod. Spawning fish are captured in shore and far out to sea 

 at the same time, while shotten and mazy ones are frequently found together. 



The escape of the young from the eggs, either in spring or autumn, can be 

 considerably delayed by keeping the water very cold, while its saltness or reverse* 

 exercises no appreciable difference. Three to four weeks has been suggested as 

 the probable time at which hatching normally occurs after extrusion. While if 

 these eggs are heaped together they become mouldy. Meyer found that in a 

 few days after being hatched they commenced preying upon microscopic forms 

 existing in the water, after a month on small Crustacea, and at the end of 

 the third month they were a little over 1| inches in length. Beyond five months 

 he could not keep them alive. The young, known as whitebait, swarm along our 

 shores in certain localities, sometimes to a great extent mixed up with sprats, at 

 other time in independent assemblages. 



Mr. Stevenson (Mansion House Street) hatched some. The spawn was 

 obtained November 10th, 1870 ; by the 17th the eyes and movements of the 

 young fish were plainly visible through a hand-magnifier, and on the evening 

 of the 24th (fourteen days after they had been taken from the parent and 

 impregnated) many shells were found empty, but only one little one could be 

 seen, for they are so minute and transparent that there is but little chance of 

 finding them in a large body of water. By enclosing the ova in a suspended 

 muslin receptacle in the tank several more were hatched out by the 29th. 

 Dr. Meyer, respecting the experiments made in the North Sea, observes that no 

 one has succeeded in rearing herrings from artificially fecundated eggs, owing 

 to the impossibility of arresting the formation of hyphse of some fungus, and 

 the difficulty of obtaining suitable food : very soon after the yolk was consumed 

 they died. 



H. Widegren, in Scandinavia, found that certain races of herring, particularly 

 the larger ones, spawn near the land on a bottom overgrown with sea-weed. If 

 this bottom is made unfit for spawning by taking up or destroying the sea- weed, 

 either by nets or any other way, the herring becomes obliged to migrate to 

 more suitable places, and consequently deserts the inlets where he formerly 

 visited regularly. " By experience gained in Bohuslan and other places, it is 

 proved that the herring is extremely sensitive in this respect, and deserts old 

 spawning places entirely if their' character is changed." Vegetation ought not 

 to.be disturbed nor refuse cast into the water. 



It now becomes necessary to consider, What do we understand by whitebait, 

 jor " white bite" as it has been termed ? Here we must first seek for the origin of 



* In the Baltic the German Commissioners ascertained that with the water at 53° the eggs 

 hatched in a week, whereas at .'$s° they took six weeks, while raising the temperature above 53° did 

 not quicken the hatching process. 



