THE LIFE-HISTOBY OF THE SALMON. 293 



In a space 72 ft. square 300 wooden boxes are placed in 

 twenty-five rows, each containing twelve boxes, on a gentle 

 slope. In the bottom of each is placed a layer of fine gravel, 

 with an upper loose coating of larger stones. A full supply 

 of water is brought from the mill-lade just mentioned by a 

 sluice and pipe, so that it bubbles up through a thick layer of 

 sand and gravel in the filtering pond, whilst on each side of 

 the aperture of exit is a wooden trough for collecting superfluous 

 mud. The sole inhabitants of this pond are Minnows and Eels. 

 From the filtering-pond the water passes by two wide pipes to 

 the northern canal which laves the upper end of the breeding- 

 boxes, bubbling up at the fourth box from each end, the water 

 then rushing into each of the wide notches at the ends of the 

 twenty-five boxes, streams longitudinally through, passing on to 

 the next, and finally plunging from the last into the lower canal 

 at the southern end of the boxes. A double sluice at the western 

 corner of this canal carries the stream to the large rearing-pond 

 further down the slope. 



The gravel and stones in the boxes are carefully cleaned 

 before collecting the ova during the spawning season, which 

 usually is between the middle of November and the middle of 

 December ; the Salmon being captured near the mouth of the 

 river Almond as it joins the Tay. The Salmon are gently held, 

 and the hand passed from before backward along the belly, 

 when the ripe ova or milt pass out by the genital aperture and 

 drop into a vessel and then the fishes are returned to the river.* 

 Fertilization being effected, the ova are removed to Stormont- 

 field the same evening. It was found in 1859 that the milt of a 

 Parr twenty months old was equally effective with that of an 

 adult male, and no difference was observed in the growth or 

 aspect of the young fishes subsequently reared. 



Having reached the hatching-boxes, the fisherman in charge 

 commences at one side of the rows and literally sows the ova 



* This method of dealing with ripe fishes should be borne in mind. On 

 one occasion an expert and an official were greatly perturbed as to certain 

 ripe Turbot which would not discharge their eggs and milt ; yet it was only 

 necessary to capture the fishes with a hand-net, gently manipulate the 

 abdomen, and a stream of ripe eggs issued at once, and were fertilized by 

 milt from the males. 



