iX)l$ Proceedings, of the Boyal Society, 



became suffused witli an inky hue at their extremities, the hroad 

 perpendicular bars or blotches on the sides were effaced, and the 

 prevailing hues of dusky brown and yellowish-white were con- 

 verted into deep bluish-black above, and into silvery white below. 

 Various other specimens exhibited by Mr Shaw exemplify a simi- 

 lar change, and some of these distinctly shew, as it were, the in- 

 termediate or transitionary state between the parr and salmon. 

 The whole, however, belonged to broods which, as formerly ex- 

 plained by the author, were the original produce of adult salni(m. 



The observations hitherto reported were made in confirmation 

 and continuance of those formerly laid before the Society by the 

 same author. But the circumstance of the male parrs in a state of 

 sexual maturity being found to accompany the female adnlt salmon 

 while she deposits her ova in the river, suggested the idea of the 

 following singular and successful experiment. In the month of 

 January 1837, Mr Shaw took a female salmon weighing 14 lb. 

 from the natural spawning bed, from whence he also took a male 

 parr weighing one ounce and a half. With the milt of the latter he 

 impregnated the ova of the former, and placing the spawn in the 

 stream of his pond he watched its development, as he bad that of 

 the salmon spawn fecundated in the ordinary way, and found the 

 hatching and subsequent growth in all respects to correspond. 

 Tiiese experiments were repeated with the same results in the 

 winter of 1838, and the parrs (taken from the river) which had 

 been used as males, were kept alive till spring, when they assumed 

 the migratory dress of young saltnon. He also tried a correspond- 

 ing experiment, by impregnating the ova of three adult female sal- 

 mon taken from the river, with the milt of three parr bred in the 

 confinement of the ponds, and the result was the same as to suc- 

 cessful hatching and final growth, — this fact, moreover, shewing 

 the constitutional strength of the pond-bred breed, and that they 

 had not deteriorated or been altered in their natural character and 

 attributes by confinement, as had been supposed. The specimens 

 used in these experiments are exhibited to the Society, that all in- 

 terested may satisfy themselves by ocidar inspection. 



One of these specimens is itself the produce of a male parr 

 and female adult salmon; in other words, it is what naturidists 

 (supposing the parr and salmon not to be identical) would call 

 a hybrid or mule. Now, it is admitted by physiologists that 

 the general rule in i/egard to these mixed produitiuns, from kinds 

 not specifically the same, is, that they do not breed ; yet this male 

 parr, originally produced from a parr and salmon, has itself become 

 the parent of a numerous and healthy progeny of young salmon ; 

 and Mr Shaw attaches great importance to this fact, the experi- 

 mental particulars of which are carefully detailed in his paper, ft 

 had, in truth, been objected to Mr Shaw's former experiments, that 

 by a forced alliance between the parr and salmon, he had not proved 

 their identity, but had merely succeeded in producing a hybrid. 

 The brood, however, in no way differs from other young sal- 

 rr.on in the parr stage, so far as external cbaracters are concern- 



