278 



Tliese 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 salmon. 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 iu the 

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

 cessful hatching and final growth, — this fact, moi'eover, 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 ocular inspection. 



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

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

 (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 regard to these mixed productions, 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. It 

 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 diflPers from other young sal- 

 mon in the parr stage, so far as external characters are concern- 

 ed ; and their procreative powers afford an additional confirma- 

 tion of their being identical. Mr Shaw moreover observes, that, 

 if the parr were a distinct species, the results of their attendance 

 on the female salmon would produce universal confusion among the 

 migratory inhabitants of rivers, " from the circumstance of the male 

 parrs, in a breeding state, occupying in great numbers the very 

 centre of the salmon spawuing-bed ; while the female salmon her- 

 self is, at the same instant, pouring thousands of her ova into the 

 very spot where they are thus genially congregated." 



Mr Shaw's experiments were conducted with great care ; have 

 been frequently verified by repetition ; and have always been fol- 

 lowed by the same results. He concludes his paper by stating, that 



