THE GURNARD FAMILY 



J27 



are somewhat larger than a walnut, in the other about as large as 

 a man's fist. They are often found between tide-marks at low 

 water. It is stated that the male guards them, and it is probable 

 that they require the attention of one or other of the parents, to 

 keep a current of water over and through them, but I know of 

 no direct observations in this case. The eggs of the sea-scorpion 

 are -fg inch in breadth, of the other somewhat less. The yolk is 

 made up of minute globules, and is of a red or orange colour in 

 the sea-scorpion, yellow or nearly colourless in the long-spined 

 species. There are several oil globules of various sizes, but 

 during development they unite together into one, which is placed 

 at the front end of the yolk in the hatched larva. 



The development occupies some weeks. The clumps can 

 often be found with the larvae just ready to hatch out from them. 

 These larvai are much larger, more developed, and more active 



Fig. 144. — Newly hatched larva of the Long-spined Bullhead, alive and magnified. 



than any larvae hatched from buoyant eggs. In fact, in adhesive 

 eggs generally there is a considerably larger quantity of yolk, 

 the development in the egg is more prolonged, and in consequence 

 of this, the fry when first hatched are in a more developed 

 condition. The larva of the sea-scorpion is about ys mm. long 

 or yV inch, that of the long-spined bullhead (Fig. 144) 57 mm., or 

 a little more than jS_ inch. The differences in character between 

 the two kinds are very slight. The head is rounded and large, 

 and the mouth and jaws well developed. The abdominal region 

 is very short, and the tail long. As usual in eggs developed at 

 the bottom, red blood is seen coursing in veins over the yolk- 

 sac. The primitive fin-membrane passes from behind the head 

 round the end of the tail, to the hinder end of the yolk-sac, where 

 the intestine opens : this membrane is enlarged at the tail end, 

 and narrower at the root of the tail. But the most characteristic 



