26 NATURAL HISTORY OF THE SALMON. 



one-fourth full of water. The female fish was 

 first turned on her back, one man holding the 

 tail, another running his hands down each side 

 from the head, and pressing lightly with his 

 thumbs, the ova were readily discharged into the 

 tub ; a similar course readily discharged the milt. 

 About 370 salmon were treated in the above 

 manner, and again returned to the river. Mr 

 Ashworth then explained how the ova and milt 

 were mixed in the tub, and the ova then taken out 

 of it with a cup and deposited in the boxes, when 

 they were covered with additional gravel. Mr 

 Ramsbottom supposed that there was put in the 

 boxes spawn sufficient for 40,000 ; however that 

 might be, there are at present about 20,000 young 

 salmon alive and thriving in these ponds, and 

 from two inches to three inches in length. Mr 

 Ashworth then, in answer to several questions 

 put by Mr Graham of Redgorton, stated that the 

 fine zinc gratings were used to prevent trout 

 and insects from getting into the ponds, as they 

 are very destructive to the salmon fry. He then 

 detailed, at some length, the mode adopted in 

 France for the artificial propagation of salmon, 

 carp, trout, and other species of fish. The boxes 

 there used were 3 feet in depth, 18 inches in 



