49 
reproducing their kind by tens of thousands per 
pair every year. A salmon weighing 20 lbs., pro¬ 
duces about ... ... ... ... 20,000 eggs. 
A trout of 1 lb. 
A pike of 44 lbs. 
A perch of 4 lb. 
A herring of 4 lb. 
A cod of 20 lbs. 
1,000 
43,000 
20,000 
20,000 
4,900,000 
>} 
j j 
> > 
>) 
eggs 
Trout and salmon, on an average, carry 1000 
to each pound v.^eight. 
From eggs we naturally come to “nests.” Fishes 
ISTests ? This may seem to some of you like the phrase 
one often hears, •“ finding a mare’s nest.” To this, I 
merely answer that fishes do make nests. I do not 
mean to say that they climb trees and build like birds 
or squirrels, though the seven-spined stickleback in 
salt, and the common stickleback in fresh water 
make rather complicated nests. Most fishes, indeed, 
do make shelters for their eggs,which are nests to all 
intents and purposes. When about to spawn the 
salmon selects a gravel bottom with a shallow quick 
running stream, such as you see above the Perth 
Bridge (where even now a few fishes may be seen 
spawning). The reason being that where the flow of 
water is rapid, there is a greater supply of oxygen to 
the eggs themselves, and to the young ones when 
hatched. The nest is easily recognised, being a 
hillock or mound of gravel with a hollow sort of ditch 
in front of it. On removing the gravel the eggs 
appear all loose in it, and seeing the delicate looking 
ova, one is naturally led to wonder that they are not 
crushed by the weight of the gravel; but, it has been 
found by actual experiment that single eggs will bear 
a weight of over 5 lbs. before they break. 
The salmon does not, as is generally supposed, turn 
up the g.:avel with its head, but by a rapid motion of 
its body raises the gravel on both sides ; the female 
turns on her side, and by strong undulations drives up 
a heap of gravel from her tail. Stones and gravel are 
easily moved under water, consequently the exertion 
required to throw up a bed of gravel is not great. 
The male all the time this is going on lies near at 
hand, on the look-out for other males, and if any un- 
