30 DAYS AND NIGHTS OF SALMON FISHING 



of December, 1837, an( l was published in the Edin- 

 burgh New Philosophical Journal for January, 1838, 

 Vol. XXIV, page 165. His third and concluding 

 communication, by far the most interesting, and 

 which has been lately received by the Royal Society 

 of Edinburgh, contains a continuance and confirma- 

 tion of the results of the experiments mentioned in 

 the two first papers above alluded to, together with 

 the very extraordinary fact, that the milt of a Parr 

 eighteen months old, and only weighing an ounce 

 and a half, is capable of impregnating the ova of a 

 full-grown Salmon. 



Before proceeding to make the experiments re- 

 lated in his last communication, he made three 

 ponds, the banks so raised, and constructed other- 

 wise in such a manner, that it was impossible for the 

 young fish to escape, or for any other fish to have 

 access to them. Accurate drawings and descriptions 

 of these ponds are given in his printed pages, now 

 before me, which he was so obliging as to present 

 me with. ' Being thus prepared," says Mr. Shaw 

 (alluding to the construction of his ponds), " with 

 every means of carrying my experiments into prac- 

 tice, I proceeded to the river Nith on the 4th of 

 January, 1837, an( l readily discovered a pair of 

 adult Salmon engaged in depositing their spawn. 

 They were in a situation easily accessible, the water 

 being of such a depth as to admit of my net being 

 employed with certain success." The fish were 

 accordingly captured by means of a hoop net. The 

 ova were then pressed with the hand from the body 

 of the female, and impregnated in the same manner 



