DEVELOPMENT AND LIFE-HISTORIES OF TELEOSTEAN FISHES. 823 



intestine. A line of the chromatophores passes along the infero-lateral region from the 

 beginning of the mesenteron to near the caudal tip, and a few exist on the dorsal part of 

 the abdominal region. A fourth branchial arch is visible. A delicate polygonal proto- 

 plasmic meshwork occurs over the surface of the yolk, as in the flounder. The walls of 

 the heart are thinner, and cellular strands pass backward to the liver. There is neither 

 mouth nor anus. The alimentary, renal, and other organs have been further developed 

 on the third day (of freedom), and the urinary vesicle sends down a fine strand of cells, 

 the precursor of the urino-genital tube. On the fifth day rapid elongation of the 

 skeletal elements of the mandible has occurred, the head has been raised, and the cranial 

 flexure diminished. The point of the snout is now in the same line as the ventral 

 margin of the liver. The abdominal pigment has increased, but there is little change 

 in the rest. The oral chamber has now burst through. The otocyst presents a ridge 

 growing up from the floor, and a chamber descending from the roof, the otoliths lying 

 on each side of the former. A lenticular mark indicates the anterior nares. The 

 mouth gapes, but only erratic movements of the parts take place. Next day the 

 mandible protrudes further, and the branchial and hyoidean arches are prominent. The 

 yolk-sac is oval and much diminished. On the seventh day blood began to pass into 

 the heart, but the death of the embryos arrested further examination. 



The newly hatched larvae of this species are very small, about 3 mm. in length, 

 and irregularly pigmented with black. They emerged in June, in about six days after 

 fertilisation, and are very active when free. In a week they are difficult to see when 

 resting on the bottom, and if stimulated they glide rapidly, seldom rising above the 

 bottom, or at any rate rising very little, and progressing with a jerking motion, the yolk- 

 sac being inferior. When at rest in the water, the head hangs slightly downward as in 

 other young fishes, and in descending they wriggle a little and elevate the anterior region. 

 They are chiefly recognised by the eyes, which are large and pigmented, and also by the 

 pigment passing along the dorsal edge of the abdomen as well as a faint line below the 

 muscle-plates of the same region. 



The post-larval stages of the haddock have hitherto escaped detection, and it is only 

 when the fish reaches the length of upwards of 2 inches, with the characters of the adult 

 fully displayed, that it has come under notice. Few authors allude to the very young 

 stages of this form, though G. 0. Sars thought he could distinguish them amongst 

 other young gadoids by their shorter and stouter form. Collktt again states that he 

 found the young haddocks 7 cm. long under Cyanea capillata* 



Gadus virens, L. — The ova of this species have not been recognised in the ripe 

 condition. It is stated by Kroyer to spawn in January. In its earlier stages the green 

 cod probably resembles the cod very closely, and follows similar habits. When 1^ inch 

 in length they come in large numbers to the margins of the tidal rocks about the end of 



* Vide Mobius and Heincke, who quote without criticism the remark of Malm that the haddock spawns in shells 

 on the west coast of Sweden from January to March ; and that in the museum at Kiel is a shell-fish on which are 

 ripe eggs. 



