Royal Society of Edinburgh. 353 



riments during the intervening period. These valuable observations 

 merit a more ample detail in our pages ; meanwhile, however, we 

 supply but a few hasty hints. 



In some prefatory remarks, Mr. Shaw met an objection to the 

 inferences from his published investigations, proceeding from respect- 

 able authority, and which resolved itself into considerations con- 

 nected with the small size and artificiality of his experimental ponds. 

 Mr. Shaw repelled this by stating that the ponds were made the 

 channel of a copious stream ; that the body of running water they 

 contained was very considerable ; that the supply of the insects, &c. 

 which constituted the food of the young fish was abundant ; and 

 that these little creatures were in as good condition as their con- 

 geners in the neighbouring river. 



Mr. Shaw's former observations led to the conclusion that the 

 Parr is nothing else than the proper fry of the regular salmon. In 

 his former paper, his experiment was carried thus far : — salmon en- 

 gaged in the process of reproduction were caught in a net ; a parti- 

 cular spot of the running stream was selected ; from this spot a 

 channel was formed which communicated with a small pool, fit to 

 become a temporary spawning bed ; into this selected spot the adult 

 female salmon w^as introduced ; by gentle pressure on her sides the 

 roe was made to flow freely from her body ; this swam down the 

 artificial channel, and was deposited in the temporary bed. Precisely 

 the process was repeated with the adult male, whose milt followed 

 the same course, and settled in the same pool. Portions of the ova 

 thus impregnated were removed into the experimental pond No. 1, 

 which, as formerly explained, was quite separate from the river, and 

 isolated from all accidental contamination : these were carefully 

 watched and found to become genuine parr. 



Strong additional circumstances have occurred within the last two 

 years, which have greatly confirmed the inference which naturally 

 flows from the above occurrence. One of these is connected with 

 the subsequent history of the little fish alluded to as j)laced in pond 

 No. 1. The brood has been watched, and Mr. S. has found that a 

 very few at the close of the first year, and the whole before the end 

 of the second, exchanged their well-known primary river livery of 

 parr, for the silvery migratory coat of the 3'^oung salmon. With this 

 change in appearance, a great change in their habits occurred : the 

 so-called parr in the pond were solitary and quiet, and if a neigh- 

 bour invaded their habitual retreat, he was speedily expelled from 

 the forbidden ground. On assuming the migratory dress, the habits 

 of the whole family becime much more active, they freely associated 



Ann. Nat. Hist, Vol.4. No. 25. Jan. 1840. 2 c 



