62 



Appendices to Twenty-eighth Annual Report 



much shaking or jolting addles the eggs, and the same infertility may 

 result in the case of milt of fishes. It should be noted also that the males 

 were held up in the cage for 13 days, and that the females were similarly 

 treated, though for a shorter period. From experience of confining salmon 

 in this way, I believe that the success of the experiment was considerably 

 jeopardised. The ripening of the genitalia is materially retarded by con- 

 fining salmon. 



In bhe Gonon Experiment, the eggs began to hatch out in 48 days, 

 although the number of dead eggs after the second week was marked. 

 Of the 22,000 eggs laid down, 11,490 remained to hatch out, and up to the 

 time of writing, 35 of the alevins have died, so that the total result is 

 11,455 fry. Last reports I have received go to show that the fry are 

 quite strong and healthy. 



First Tweed Tried. — The milt was received at Chester Fishery Office on 

 31st December, 1909, and 28,000 eggs were fertilised. Transit in this 

 case took 18 hours. The first hatching out commenced in 50 days. 

 Unfortunately the " dry " method of fertilisation was not followed in this 

 case. In seven weeks the death rate had amounted to 13,371. 



Second Tweed Tried. — The milt was received in 40 hours, and 7000 eggs 

 were fertilised on 1st January, 1910. In seven weeks the death rate 

 amounted to 411, a much better result than in the first trial. I have not 

 received particulars as to the subsequent development, and am therefore 

 unable to state why the result came to be considered a failure. 



Third Tweed Trial. — The milt was received on 3rd January, 1910, 

 having been 63| hours on the way. Only 4000 eggs were treated, and 

 2000 of these were regarded as fertilised. The eggs do not appear to have 

 " eyed " well, and the death rate during the first four weeks was respectively 

 11, 24, 81, 156. I understand that all subsequently died. 



The result of the Conon-Dee experiment is, however, sufficient to show 

 that this mode of crossing can be successfully accomplished. 



