190 NATURAL HISTORY OF THE PAR. 



ordinary laws of nature, obeyed by every other 

 creature ; and still more so, that the offspring of 

 such a union should be, as the par undoubtedly 

 is, both in respect of its various spots and marks, 

 as also in form and general appearance, one of the 

 most perfect examples of constancy that nature 

 can produce. Besides these objections, it should 

 be recollected that there are many species of trout, 

 as also several species of salmon, and assuming for 

 argument, the possibility of such a union, it would 

 necessarily produce some variation in the offspring; 

 but none such is found in the par, it being always 

 alike. Although its assigned parents the trout 

 in particular continually exhibit every variety of 

 form, marks, spots, size, colour, and appearance 

 that imagination can conceive. It is said that this 

 union between trout and salmon is the work of 

 necessity, and takes place only when the male or 

 female salmon has been destroyed ; but if no 

 instance of the production of hybrids can be 

 shown amongst carp, tench, roach, dace, and other 

 fresh water fish, closely and artificially confined, 

 as they continually are, in small ponds, ditches, c., 

 it is clear that the necessity for a cross amongst 

 fishes in general does not exist ; and if so, it is 

 absurd to plead the necessity for such inconsistency 

 amongst trout and salmon in particular, wholly 

 unconfined as their theatre of existence must 

 necessarily be, save by the ocean itself. 



