CHAPTER VIII. 
HATCHING THE EGGS. 
Glass grilles—Their cost—Their advantages—Cleaning the hatching boxes— 
The egg-shells—Artificial ova beds—Settling pond—Filtering bed— Wire grilles— 
Destruction of ova left to Nature—Advantage of artificial beds—Californian 
baskets—Repairing grilles—Overcrowding—\WVay of economising space —Compact 
storage box. 
‘Tee are more ways than one of dealing with trout eggs. 
After a careful study of the various systems in use, and after 
weighing well the evidence, I give my verdict, and give it un- 
hesitatingly in favour of the glass grille system. I have myself 
used grilles for more than twenty-five years, and have not yet 
met with anyone who can give one valid reason for their dis- 
continuance. Of the arguments brought to bear, that which at 
first seemed the most plausible was the one of cost, but it would 
not stand scrutiny. . 
The chief item consists of the glass tubes or rods; but 
seeing that, apart from actual breakages, glass will last for ages, 
there is little to allow for depreciation. As to breakages, we all 
know that glass will break, but with proper care there is but a 
small loss from this cause. I have carefully noted that which 
takes place in my own hatcheries, and find that out of every ten 
thousand glass tubes, about seventy-five per annum get broken, 
or considerably less than one per cent. As for the wooden parts, 
it is found in practice that they are less perishable than metal, 
for with care they last for twenty years, and are good at the end 
of that time. Grilles can be purchased ready-made for four 
shillings and sixpence each, and a grille holds from 3,500 to 
5,000 ova. Taking 4,o00 as an average, and allowing that a 
grille only lasts twenty years, then a grille incubates in the course 
