THE SALMON 195 



tissue, an outgrowth of the general envelope of the body which 

 underlies the epiderm or outer skin. Of the purpose of this 

 peculiar excrescence it boots not to treat, though there be 

 many who have done so. Various functions have been 

 assigned to it on purely speculative grounds. Some would 

 have it to be a weapon of offence ; but it seems to be the 

 very reverse of this, diminishing the destructive power of the 

 jaws by partially closing the mouth. All we really know 

 about it is that it appears on the males periodically at the 

 breeding season, and is re-absorbed when the reproductive 

 function is finished and the fish becomes a kelt. In old 

 males, this knob is never completely absorbed, and the 

 head becomes permanently elongated in comparison with that 

 of the female. But it is to be noted that occasionally 

 females develop the knob also, though not to such an 

 extent as the males. 



One use often, but erroneously, ascribed to the knob or 

 hook, is that of preparing a nest or bed for the spawn ; and 

 Process of ^ shows how difficult it is to stamp out an error 

 spawning. wn ich has once received currency that people may 

 still be heard repeating this silly fable. So long ago as 1656, 

 Richard Franck, as observant in zoology as he was bitter 

 in theology, accurately described the process of spawning 

 as he himself had watched it. The female swims upon a 

 gravelly shallow, where the current is brisk, but not violent ; 

 and, having chosen a spot to her fancy, rolls upon her side and 

 flaps her tail rapidly so as to fan up the gravel, thereby ex- 

 cavating for herself a hollow. This trough is usually called a 

 " redd "* in the north, and when the fish have not been delayed 

 by want of floods from ascending the river, several days may 

 be occupied in making it ; but when salmon have been retarded 

 by drought in arriving at the spawning-ground, the redd is 

 excavated in more summary fashion. So soon as it is finished 



* I.e., a place made " ready " or prepared. " Redd me a place " in 

 Lowland Scots means " Prepare room for me." 



