GURNARDS. 
83 
I the thread is semi-fluid, but by exposure it 
I solidifies; and hence contracts and binds the 
: substances forming the nest so closely together, 
I that it is able to withstand the violence of the 
I sea, and may be thrown carelessly about without 
I derangement. In the centre are deposited the 
i ova, very similar to the masses of frog-spawn in 
j ditches. . . . 
! It is not necessary to enter into minute par- 
:: ticulars of the development of the young, any 
' further than to add that they were the subject of 
I observation till they became excluded from the 
; egg, and that they belonged to the Fifteen-spined 
■ Stickleback {Gasterosteus spinachia). Some of 
' these nests are formed in pools, and are, con- 
I sequently, always in water : others are frequently 
I to be found between tide-marks, in situations 
- where they hang dry for several hours in the day ; 
I but whether in the water or liable to hang dry, 
‘ they are always carefully watched by the adult 
I animal : on one occasion, I repeatedly visited one 
j every day for three weeks, and invariably found 
! it guarded. The old fish would examine it on all 
; sides, and then retire for a short time, but soon 
, returned to renew the examination. On several 
occasions I laid the eggs bare, by removing a 
portion of the nest ; but when this was discovered, 
great exertions were instantly made to re-cover 
them. By the mouth of the fish the edges of the 
opening were again drawn together, and other 
portions torn from their attachments and brought 
over the orifice, till the ova were again hid from 
view : and as great force was sometimes necessary 
to effect this, the fish would thrust its snout into 
the nest as far as the eyes, and then jerk back- 
