80 SALMONIDiE OF BRITAIN. 



During the winters of 1884-85, and also of 1885-8f3, experiments were instituted 

 ou this question at Cheltenham {see p. 37), all of which fully corroborated the 

 view that salt water is fatal to the eggs of salmon. 



It has been asserted, and is still maintained by some, that redds are formed 

 by salmon burrowing into the sand or gravel with their heads, or the male with 

 his hooked jaw. 



When one considers the structure of this fisli, it must be evident that it would 

 . be impossible the male could dig a hole in the bed of the river with the hook 

 on the lower jaw, because it possesses no neck, nor the power of moving its head 

 np and down, as observed by Mackenzie {View of the Salmon Fisheries of 

 Scotland, 1860, p. 175), without a corresponding movement of its entire body. 

 While even if the fish retreated a few yards to give it an impulse, it would still be 

 necessary for it to raise its tail out of the water at an angle of -15° to enable it, 

 like a pickaxe, to knock its snout against the gravel, or, for anything the poor 

 creature knows, against a stone. Irrespective of the injury such a proceeding 

 would occasion to the fish, the gravel disturbed by the snout would enter the 

 fish's mouth to the detriment of its respiration : and the knob cannot be a 

 necessity for this work, for in how few trout or char do we see it, yet they all 

 form a redd or nest. 



Of course the nearer the sea suitable spawning grounds are, the more valuable 

 do they become to the fishery at the mouth of the river. Salmon eggs are 

 deposited in rivers, rarely near their mouths, where the tide or the current would 

 be too strong for the j-onng fish to live in, but often in small and even mountainous 

 streams, where the water is pure and shallow, having a gravelly bod which permits 

 the redd or nest to be constructed,* while deep pools in the vicinity allow the 

 breeding fishes to retire into them for rest The salmon ascends our rivers to a 

 suitable spot, and in the gravel at the bottom of the stream constructs its redd, 

 which work would seem to be the occupation of the female. She lies on one side, 



ford, which is affeoteil by spring tides, but only in a slight degree, half-a-dozen redds are generally 

 to be found every winter. Mr. .J. Jackson (Field, December 20th, 1884), writing of the Yorkshire 

 Esk, recorded, respecting salmon ova, that "it is an interesting question, however, as to what 

 amount of brackish water will destroy it ; and, as we have a lot of spawning fish depositing their 

 ova in the stream, just below Euswark Mill-dam, over which they cannot get when heavy in 

 spawn, and up to which spriug tides rise about two or three feet, covering the sj^awn beds for 

 about two hours each tide for some three or four days at each period of high tides. Some ova 

 from fish spawning there was procured and placed in a box in the gravel at that spot. This was 

 done in order to ascertain whether they would come to life. Though nothing came of the experiment 

 for the first two years, it was asserted that this year (1884) a good portion of them were hatched. 

 Another account, however, stated that some of the ova were removed from this box, and hatched 

 in a basin of fresh water in the village brook, whereas all that were left in the box died. 



Sir J. MatJieson, during the winter of 1801-62, had two portions of impregnated salmon eggs 

 used, one for trial in brackish water of specific gravity 1015°, the other in fresh. They were held 

 on a wire cloth in a glass vase with a tap at its bottom, and the water was changed daily. During 

 the first ten days the ova in the brackish water did not appear to suffer, but no longer ; no further 

 development was observed in them, and they all died, while those in the fresh water made 

 })rogress, and in due time were hatched. Dr. Davy [PJn/sioIopical liesciirclietf) tried the effects of 

 a solution of common salt in water, having a specific gravity of 1020°, on a salmon egg, the 

 embryo in which api^ears to have succumbed in a few hours over two days. The ovum of a Dee 

 salmon in similar water, or a specific gravity of 1007°, was hatched at the end of about forty- 

 eight hours ; the young was very languid, but at the end of the fourth day was still alive. 

 Brown, in his account of the Storinontjic/d Ji.rjjcrimetit.i, 18C2, observed : — " We have also taken 

 ova which had been recently manipulated upon, and dropped it into sea water, which destroyed 

 it almost instantaneously, only a few of them becoming opaque ; in the greater jiortion of them 

 the yolk became shrivelled up and contracted." Mr. Brander, in Tlie Fivld, remarked upon 

 having observed some holes scooped out in the gravel close to the mouth of the small river 

 Lossie (near the Spey), and within the reach of the salt water, and here he found in January, 

 1882, a few salmon working at their redds, which were within a mile and a half of the sea, and 

 covered once a fortnight at spring tides with quite salt and undrinkable water, for perhaps an 

 hour's time. 



* Very complete accounts have been given as to the manner in which the salmon redd is 

 constructed. Captain Francks {Nortlu'iii Mciiioirx, about a.d. 1650, p. 167) recorded how he 

 watched a female until she arrived at a bed of sand where she was scarcely covered with water, 

 certainly not exceeding a foot in depth, here, with her tail, she wriggled to and fro so long and 

 oft until he saw a flat blueish stone, over which she oft times contracted her body and ejected 

 her eggs. The male having arrived at the same spot dilates his fins, and flutters about, and 



