126 FISH HARVESTING. 
lax order. No sooner has this lady, his first 
love, taken her departure, than he at once 
seeks another, introduces her as he did the 
first, and so on wife after wife, until the nest is 
filled with eggs, layer upon layer—milt being 
carefully deposited betwixt each stratum of 
ova. As it is necessary there should be two 
holes, by which ingress and egress can be 
readily accomplished, so it is equally essential in 
another point of view. To fertilise fish-eggs, 
running water is the first necessity ; and as 
the holes are invariably placed in the direction 
of the current, a steady stream of water is thus 
directed over them. 
For six weeks (and sometimes a few days more) 
the papa keeps untiring sentry over his treasure, 
and a hard time he has of it too: enemies of all 
sorts, even the females of his own species, having » 
a weakness for new-laid eggs, hover round his 
brimming nest, and battles are of hourly occur- 
rence; for he defies them all, even to predatory 
water-beetles, that, despite their horny armour, 
often get a fatal lance-wound from the furious 
fish. Then he has to turn the eggs, and expose 
the under ones to the running water: and even 
when the progeny make their appearence, his 
domestic duties are far from ended, for it is said 
