34 
ANIMAL CURIOSITIES 
about an inch in diameter, and held together 
by a fluid secreted by the fish’s kidneys. It is 
fashioned by the male with the aid of his mouth 
and snout, and rests upon the bed of a stream 
in shallow water. When all is ready, the 
female enters one end of the nest that has been 
left open by the male, and having deposited 
her eggs inside she makes an exit at the other 
end and passes out. 
When once the ova are laid in the nest, the 
male stands guard over them and ensures that 
they receive a sufficient supply of oxygen for 
their needs by gently fanning his breast fins 
backwards and forwards, thereby causing a 
continual supply of fresh water to circulate 
around the home and its precious contents. 
After a period of about ten days, the young, 
which are very small and so transparent as to 
be scarcely visible to the human eye, hatch 
out. 
The devoted father then becomes even more 
watchful than before, never leaving his charges 
night or day, and driving away all intruders. 
Only when the fry are sufficiently grown to be 
able to look after themselves does he relax his 
vigilance. 
The habits of the ten-spined stickleback are 
very similar to those of the foregoing, except that 
its nest is placed amongst foliage and roots of 
