ARTIFICIAL HATCHING OF SPAWN. 57 



cause the eggs to shoot out in one continued stream, 

 bursting forth like peas from a pea-shooter. When 

 the fish is unripe, if you force out the eggs, you 

 damage them, by the pressure in the first place, and 

 you rupture the membrane they are attached to in the 

 second, so that blood will often be discharged with 

 the ova, which is of course immature and useless ; 

 you may also seriously damage the parent fish. 

 Whereas, if the ova be taken from her at the proper 

 time when the operation is over, it is not an exag- 

 geration to say that she will dart off as actively as 

 ever, and as if delighted to be rid of her burthen. 

 The fitness of the male fish may easily be decided, ? 

 as, if ready, the milt flows with the least pressure, * 

 and often without. 



The method of holding the fish while expressing 

 the spawn usually recommended is to hold the fish 

 tail downwards, with moderate firmness, around the 

 head, or rather shoulders, with the left hand, the 

 belly being turned outwards and the back towards 

 the manipulator's body, the points of the fingers and 

 thumb being also turned outwards. The right hand 

 then grasps the fish a little above the vent, so that 

 the ball of the thumb is upon the belly of the fish. 1 

 The right thumb is then moved softly up and down 



1 See fig. 2 in the Frontispiece. 



