448 SALMON AND TROUT. 



or the wood-work only may be * charred.' Varnish or paint, 

 however, preserves the zinc, and prevents oxidation. The 

 punctured pipe must be raised a quarter of an inch from the 

 bottom, by means of little feet soldered on, as in case any fish 

 escape from the trays in manipulation, they would be killed by 

 attempting to get under the pipe if it is laid on the bottom. It 

 is often necessary to thin out the young fish, and the bottom of 

 the troughs thus gives a large amount of extra space, and the 

 fish can be drawn off by the waste pipe when required. 



One looks back with much interest to the time when these 

 experimental operations were commenced. How well I re- 

 member my first day's trout spawning ; how careful I was that 

 the can containing the freshly taken ova should not be shaken 

 on the journey of three miles home : the least jostling or 

 swinging of the can sent a feeling of horror through me ; and 

 what an excited state of uncertainty I was in for the first few 

 weeks, wondering whether with all the clumsiness in taking 

 the eggs, any of them would 'hatch out' I have since 

 learned that freshly taken ova can be sent long distances by 

 rail without danger, and I prefer to send them in water rather 

 than moss, as they can be transferred to the hatching troughs 

 more quickly, and with less risk of concussion. The ova will 

 not bear the same amount of shaking and disturbance forty- 

 eight hours afterwards, but they may be examined with a glass 

 tube, and carefully replaced in the troughs without injury, 

 from the day of taking : anything approaching concussion, 

 however, kills them, until the tissues of the fish are firm and 

 their eyes are visible. 



THE COLLECTION OF OVA. 



When everything in the hatching-house has been tested, and 

 ascertained to be thoroughly sound and in order, the ova is to 

 be procured. 'First catch your hare,' is applicable here. I 

 remember in former years the great uncertainty and risk there 



