564 ^^^ SHAW'S EXPERIMENTAL OBSERVATIONS ON THE 



barren :" consequently, upon this principle — a law in the economy of nature — 

 the parr and salmon are really identical in species, as proved by the fact now 

 narrated, of the young produced between them having actually the power of re- 

 producing their kind. 



Apart from these experiments, it was at one time held, that the parrs found 

 in their native streams were hybrids, from the anomalous circumstance of the 

 males being always found in the autumn with the milt matured, while females, 

 of a corresponding size, could at no season be found exhibiting the least approxi- 

 mation to a breeding state.* However, this idea, if it ever was seriously enter- 

 tained by scientific men, has now given way to the opinion " that they are a 

 distinct species, and have no connection whatever with the migratory salmon."f 

 Were the parr a distinct species, the result of their attendance on the female 

 salmon would have the effect of producing universal confusion among the migra- 

 tory inhabitants of rivers, from the circumstance of the male paiTS in a breeding 

 state occupying in great numbers the very centre of the salmon spa\\Tiing bed, 

 while the female salmon herself is at the same instant pouring thousands of her 

 ova into the very spot where they are thus genially congregated. 



Had these extraordinary results proceeded from a solitary experiment, there 

 might have been some ground for believing that I was probably deceiving myself, 

 and, consequently, misleading others, — a fear I myself at first entertained. But 

 after such a series of experiments, made with all possible care, and uniformly 

 ending in the same results, the fact can no longer, I conceive, admit of doubt. 

 Having altogether within these last two years, made eight distinct experiments by 

 artificially impregnating the ova of the salmon with the milt of a corresponding 

 number of male parrs from the river, besides three experiments with those of 

 eighteen-month-old parrs from the pond — each with perfect success — I trust that 

 I have thrown some interesting light on the breeding of parrs, — a subject which 

 has hitherto defeated all inquiry when sought after on the principle of then- breed- 

 ing among themselves as a distinct species. 



* Solitary instances have occurred of large female parrs having been found in salmon rivers with 

 the roe considerably developed, and I find, by detaining the female smolts in fresh water until the end 

 of the third winter, that individuals are found in this comparatively mature condition. From this fact, 

 therefore, it may be inferred, that the large parr, either male or female, of nine and ten inches in length, 

 which are occasionally found in rivers, are the young of the salmon, which, for some natural reason, had 

 not been prepared to migrate at the ordinary period, and had, therefore, remained for another year in 

 the fresh water. 



■[■ Recent experiments having been made on the young of the salmon by very competent individuals, 

 it is now admitted that they " remain one year in the river before they go to the sea as smolts." How- 

 ever, owing to these fishes having escaped the observation of those individuals during the intermediate 

 stage, that is, from the ovum up to the length of three inches, they were actually twelve months old at 

 the commencement of the experiments referred to by Mr Yarrell, in place of being the " fry of that 

 year." — See Mr Yarrell's Supplement to British Fishes. 



