212 THE BLENNY FAMILY. 



takuu by both parents is not common amongst fishes, since in 

 cases where any attention is paid to them it is the males which 

 do so, as in the sea-horses, sticklebacks, lumpsuckers. Alius and 

 others. 



The egg has a diameter of 171 mm. ('076 in. Mcintosh and 

 Prince), with a colourless yolk, and a single oil-globule about 

 "51 mm. ('OIGG to 016 in. Mcintosh and Prince) in diameter, 

 with a granular area beneath it (Plate II, fig. 4). The capsule 

 is thin and fragile, so that it is impossible to detach a single 

 egg from the rest without rujDture. Mr Holt found that the 

 egg reached the eight-cell stage at the end of the first day. 

 At the end of the second day there were sixteen cells or 

 generally a mulberry-stage, with the yolk drawn into an apical 

 prominence within the growing disc. Steady progress was 

 made day by day — so that on the seventh day the germinal 

 cavity had formed, and on the 11th the blastopore had closed. 

 On the 12th day the rudimentary eyes appeared, on the 14th 

 traces of the heart, and on the 21st the rudimentary ears, while 

 a slit was visible in the gut on the 25th day. No pigment was 

 yet present. 



The hatching period is considerabh' over a month, probably 

 about six weeks, after fertilization. 



The larva (Plate VIII, fig. 5) measures just over i of an 

 inch (1-^), and is extremely translucent, the only dark region 

 being the pupil. The snout is blunt and the head large, with 

 very large ear-capsules. The most remarkable features are the 

 extreme length and thinness of the young fish, its eel-like 

 form, the great length of the gut, and the character of the 

 yolk-sac, which is directed somewhat forward. The latter is 

 not of great size, and the yolk-proper is of an elongate ellipsoidal 

 shape with a faint opacity, and having in its lower anterior part 

 a single oil-globule of crystalline translucency, very slightly 

 tinged with ochre, and surrounded by a coat of protoplasm. 

 The liver entirely covers the posterior surface of the yolk — 

 projecting as a long cellular organ from the abdominal cavity 

 — and insinuating itself between the hypoblastic covering of 

 the yolk and the thin yolk-sac. The gall-bladder occupies 

 the upper and posterior portion of the liver — -just at the angle 



