1 66 How to obtain it. 



an accessory hatchery, and in addition to this there are several 

 excellent springs on the estate that have not as yet been used 

 at all. 



fl was obliged to sacrifice the Troutdale hatchery and ponds 

 in Cumberland owing to the shortness of the water supply, and 

 would warn others against falling into the same trap. Fish culture 

 in those days was on a much smaller scale than it is now, and the 

 prices of ova and fish much higher. Without an efficient water 

 supply cultivation on anything like a paying scale is quite hopeless. 

 There should at all times be enough, and plenty to spare, so that 

 in any emergency there is an ample supply to fall back upon. 

 | Through a box containing twenty thousand ova, from five to ten 

 I gallons a minute should be used, and this will do for a set of five 

 or six of such boxes. The quantity of water is increased as the 

 hatching time approaches, and after hatching, fifteen gallons a 

 minute are sometimes run through each box. 



I have already briefly traced the development of the embryo 

 up to the formation of the chorda dorsalis or notochord. When 

 about half incubated the two eye spots will become clearly visible, 

 and as soon as they are fairly well developed the ova will bear 

 handling, and an egg at this stage is a most interesting object 

 when viewed under the microscope. The circulation of the blood 

 can be distinctly seen as it courses along the chief arteries and 

 some of the veins, in its passage to and from the heart, the 

 pulsation of which may also be detected. The future skeleton of 

 the fish may be traced, as well as the muscular fibre and tissues 

 of the body, and from this day forward the whole presents an 

 increasingly interesting object, the developing progress of which 

 may be watched daily. Possibly during the first examination the 

 tail of the fish may be seen to be possessed of a free movement. 

 If not, it soon will be, and the deepening of the colour of the 

 blood will also be observed about the same time. 



The accompanying figure represents the ovum of a trout in a 

 forward state, as viewed under the microscope. Owing to the 

 position in which it is placed only one eye (i) is in focus. The 

 breathing apparatus or gills (2) are very distinctly seen, whilst the 

 heart (7) may also be detected and the pulsations distinctly noted, 

 although, being a little out of focus it does not show out as clearly 



