SALMON AND TROUT CULTURE, 453 
TREATMENT OF THE OVA. 
As soon as impregnation takes place, the micropyle closes, 
and water cannot enter except through violent concussion. 
When the ‘germ’ has risen, and ‘segmentation’ begins, the 
ova shouid be disturbed as little as possible. After this, if the 
hatchery is well regulated, nothing short of violence or absolute 
neglect can prevent the regular progress of nature, and the eggs 
will, in due time, hatch. 
The period of ‘incubation,’ as it is sometimes called, extends 
over fifty to seventy days in water of 46° to 50° Fahrenheit, and 
during this period the pisciculturist’s labours are not very exces- 
sive, provided he has everything in first rate order, and a good 
percentage of fertilised eggs. The time occupied in picking out 
white (that is dead) ova, and any foreign substance which may 
appear, is inconsiderable, and it is not necessary that this should 
be done every day ; three or four times a week is often enough, 
unless the temperature rises, in which case ‘fungus’ and ‘byssus’ 
grow more fapidly. 
A number of good eggs are sometimes spoilt by the incessant 
disturbance caused in hunting after a few bad ones, and awk- 
wardness in removing them. Personally I allow no one to 
touch my ova until they have been in the water twenty days, 
undertaking all the picking over myself during that time. A 
few minutes at the different troughs is all that is required. 
If ova are sent to the Antipodes, they should be packed 
and placed on board ship as soon as possible after they are 
taken from the parent fish. The voyage is too long if packing 
is delayed until the eyes appear ; and as the temperature in 
Australia and New Zealand is at its highest in December and 
January, it is advisable to send eggs of late spawners, so that 
they arrive there at a cooler season, viz. April or May. 
The first consignments of ova which arrived in New 
Zealand were probably those packed by Mr. Youl and Frank 
Buckland in 1864 and 1873, and were collected from the 
