166 SALMON. 



sight cannot be made to perform the function of the ear, nor 

 the nerve of the latter that of the tongue; and also that the 

 nerves of common sensation cannot supply the place of those 

 which direct the actions of muscular motion, although no skill 

 in the use of the microscope has hitherto been able to discern 

 a difference in their structure; it follows further that the receptive 

 brain in one species of animal is not capable of eliciting the 

 essential thoughts or instinctive feelings which are the natural 

 characteristics of another. It is probable that the ordinary 

 nervous fibres of the body of every separate creature possess 

 some specific or peculiar mode of action in the conveyance of 

 impressions; but it is the central organ which gives them their 

 proper tone, from which the character of the race is formed. 

 It is among these constant characters of the species, as it is in 

 a large portion of the family, that we find the Salmon is not 

 able to sustain life under a heat of climate that shall exceed 

 what is found within the temperate regions of the earth; and 

 it is known to be most at home and in greatest abundance as 

 we proceed towards the north; although there is a limit also 

 in that direction, and our more common species is compelled 

 to shrink from the biting severity of the icy sea. Thus although, 

 as we shall have to shew, the roe of the Salmon is quickened 

 into development in a shorter time in a mild climate, and by 

 the application of a moderate degree of artificial heat, than when 

 exposed to the icy cold of a northern river, and that the fish 

 itself is so conscious of this as to refuse to ascend to its spawning 

 bed when dissolved snow or floating ice is in the way, yet Dr. 

 Davy has proved that in a heat above seventy degrees the 

 young will not come to life. 



Through Sweden and Norway to the further bounds of 

 Scandinavia the Salmon is in plenty, together with other species 

 not known with us; and in the north of Scotland, as also in 

 the Orkney and Shetland Islands it is said to reach its highest 

 degree of beauty and perfection. It is to be remarked, however, 

 that perhaps from the nature of the water, and the food, with 

 no little difference of climate, which may have impressed a large 

 amount of peculiarity on the local varieties, the season of its 

 chief excellency for the table is different, and even opposite in 

 different districts; as are also the times and circumstances of its 

 annual emigrations. In Scotland and the north of Europe, 



