Flow to obtain it. 161 
natural habitats, and should it make its appearance, depend upon 
it something is wrong somewhere. Three conditions are necessary 
for the avoidance of Saprolegnia -—(1) Darkness ; (2) thorough 
cleanliness throughout ; (3) and all wood to be carbonized. 
Light is highly favourable to its growth, and darkness is 
unfavourable. Darkness is also good for the eggs, and light is 
the reverse ; indeed too much light is calculated to injure the 
embryos. Therefore, keep the boxes always covered. As regards 
cleanliness it should not be necessary to say much, and yet I 
know it is sadly too often the case that for want of it the eggs 
suffer. The filters should be thoroughly effective, and every 
precaution taken to keep the hatching boxes perfectly clean during 
the period of incubation. Every scrap of woodwork below water- 
line should be charred, and all the joints and knots or any other 
places that look at all suspicious should be varnished also the first 
season. For the second season at least two coats should be 
applied, and each succeeding season afterwards one or two coats, 
as may be deemed desirable. Especially about any nail heads 
and the corners and crevices of the grilles should the varnish be 
applied. 
The inside of the boxes should never be too roughly scoured 
out after they have been varnished for the season. It must be 
remembered that every scratch or puncture which lays bare the 
wood, creates a suitable médus for the germs of the fungus. I 
have seen cases in which such little regard has been paid to this 
that there has been little cause for wonder at an outbreak of the 
deadly pest. Should anything go wrong with the filters and the 
eggs get covered with sediment, there is at once a danger of 
fungus making its appearance. The two things often go together. 
The eminent American fish culturist, Livingstone Stone, 
says :—‘‘ There is no word in the fish breeders’ vocabulary that is 
so associated with loss and devastation as the word ‘fungus.’ 
There is nothing with which he has to deal that is so insidious 
and deadly. This silent invisible foe is sure to come if any door 
is left open for its entrance. It often fastens its irrevocable grasp 
on the eggs, without giving any sign of its approach. Once 
present in the water it spreads over everything. It cannot be 
removed. It never lets go its hold. It is fatal in its effects.” 
M 
