FECUNDATING THE OVA OF THE SALMONID^, ETC. 85 



spring of last year, and in more than one of tlie provincial 

 papers ; and Dr. Robertson, of Dunkeld, was named as the insti- 

 tutor and reporter of the trial. Considering the manner in 

 which this statement was made and received, and the practical 

 conclusion deduced — that no longer any trouble need be taken in 

 the artificial mode of breeding to obtain the milt to apj)ly to the 

 roe — I have thought it worth Avhile to give the subject some 

 attention, on the supposition that the result, as stated, may have 

 been accurate; being, as it appeared to me to be, within the 

 limits of i30ssibility ; though I cannot say, keeping in mind the 

 structure of the male and female fish, and all the information, 

 hitherto collected respecting the manner in which the generative 

 process is carried on by them, that it is within the limits of 

 probability." 



Dr. Davy then refers to p. 17 of Young's "N'atural History of 

 the Salmon," for his " negative results" of his experiments on the 

 unimpregnated ova; that is to say, for his never having found 

 one ovum, unimpregnated with milt, productive. 



The Doctor having mentioned two trials on some unimpreg- 

 nated ova of the Clicm\ which gave the same negative results, 

 adds: — " On the 2nd of December (1853) I procured some eggs 

 from two Charr taken" on the 25th of November from Winder- 

 mere, from a breeding shoal* in that lake, " and kept in company 

 with male fish in a well fed by a small stream. The eggs, ob- 

 tained by pressure to the abdomen, were the few remaining, the 

 greater portion having been previously shed, as was manifest from 

 the lankness of the fish. From this circumstance, they seemed 

 peculiarly favourable for the trial, on the hypothesis of the possi- 

 ble admission of the spermatic fluid ab externo. But the result 

 was equally negative with the foregoing. The ova were -put into 

 water, the same as that used with the impregnated, fertile ova, 

 and under the same circumstances; all underwent no change, 

 excepting that denoting loss of vitality." 



* To those who wish to prosecute this inquiry further, I may here observe, that the 

 Charr " deposit their spawn on a weedy bed" upon a rocky ground, and not in gravel. 



And the season of the spawning of another English lake species of the Salmonidoe 



Schelly, or Gwiniad {Coregonus Lavaretus)—iB about Michaelmas; and "the place, a 

 weedy shoal ;" where, upon water-plants, its ova are to be found. (J. H.) 



