562 MR SHAW'S EXPERIMENTAL OBSERVATIONS ON THE 



traordinary results of these experiments, although made with the utmost possil)le 

 care, induced me to defer giving them publicity until I had repeatedly verified 

 the fact. I, therefore, removed this brood to another pond, apart from all other 

 fish, where they had an abundant supply of insect food and wholesome water ; 

 and again, eai-ly in the following January (1838), I repeated the experiment by 

 taking another female salmon, weighing 1 4 lb., and two male pan-s from the 

 same spa^^^^ing bed (See parent specimens marked A), and impregnated two lots 

 of her ova with the milt from the two parrs, and afterwards placed them in two 

 different streams, inclosed in boxes open at the top, temperature 45°. The extreme 

 severity of the weather which succeeded had, however, nearly proved fatal to the 

 whole. On the evening of the 8th January, the day on which I took the parents 

 fi'om the river, the frost set in, and continued with such intensity for a succession 

 of many weeks, that the wild fowl generally, and the wild ducks in particular, suf- 

 fered severe privations, and in the course of their wanderings in search of food they 

 unfortunately stumbled on my boxes of ova, one lot of which they wholly de- 

 voured, to the amount at least of 500. My feelings of mortification and disap- 

 pointment on the discovery of this unforeseen disaster may readily be conceived. 

 However, on examining my other box, I found there were still a few remaining, 

 which I carefiUly collected, and put into a place of greater safety. The progressive 

 growth of these, from the impregnation of the ova up to the age of eighteen months 

 (See specimens A), has also been uniformly the same as those produced by male and 

 female adult parents, and reared under similar circumstances. 



As a further illustration of the singular economy of the salmon in then- na- 

 tive streams, I have yet to detail another experiment or two, not less interesting 

 than conclusive. In December last (1838) I took a female salmon fi'om the river 

 weighing 11 lb., and fom* male parrs from the same spawning bed. After im- 

 pregnating fom- different lots of her ova, one lot to each individual pan', I placed 

 the four pairs in a pond, where they remained until the following May, at which 

 period they assumed the migi-atory dress. (See specimen No. 13.) The ova were 

 placed in streams to which no other fish had access, and where they became ma- 

 ture in a similarly progressive manner to those already detailed, thus clearly 

 demonstrating that the young salmon of eighteen months old, while yet in the 

 paiT or early state, actually perform the duties of a male parent before quitting 

 the river.* 



* As I believe it has been objected to my views, or rather practice, regarding this mode of impreg- 

 nation, that the generative influence may have been in some other way effected than through the me- 

 dium of the parr, I therefore took every means to prove the truthful results of luy experiments by vary- 

 ing in some measure their conditions. Thus, in two instances, I took a portion of the ova from a female 

 salmon, and placed them, without impregnation, in a stream of pure water. The result was as I antici- 

 pated: — up to the termination of the general hatching season they exhibited no appearance of vitality. 

 The female from which one lot of ova was taken, and placed in water without impregnation, was the 



