St. Andrews Marine Laboratory. 431 



the dorsal fin somewhat resembling Arabic characters. A 

 darker band runs along the lower lateral region, and in this 

 are a series of silvery spots. The dorsal fin is marked as in 

 the adult. The coloration thus indicated is present before 

 the extrusion of the young fish. The yolk-sac is almost 

 absorbed, only a slight enlargement occurring in this situation. 

 They seek the shelter afforded by crabs, stones, submerged 

 wood, and similar structures, since they are readily devoured 

 by the young cod, haddock, whiting, and other fishes (including 

 their parents). When unmolested, however, as in a separate 

 vessel, they stretch themselves at various heights on the hori- 

 zontal branches of Eudendrium and other zoophytes, and feed 

 on the hydroids and minute crustaceans that lurk amongst 

 the twigs. 



In the ovary the embryos lie over each other in a compact 

 mass ; yet in life the fluid in the chamber not only moistens 

 the branchial apparatus, but enables them to glide over each 

 other with ease. The ovarian cavity is single, and its wall 

 is comparatively thin. Moreover, stretching inward from the 

 latter are numerous long villous processes, which in shape 

 are often clavate, narrow at the base and wide at the tip. In 

 some the tips are expanded so as to form somewhat flattened 

 sucker-like surfaces. The wall of the ovary presents in trans- 

 verse section a thick epithelial layer externally (PI. XVI. 

 fig. 1, a), while the stroma beneath consists of mixed fibres 

 and cells (b), the former including a considerable proportion 

 of muscular fibres and the latter many nucleated cells. To 

 this coat are attached the membranous vascular lamellae just 

 mentioned, and which, when viewed as transparent objects 

 (PI. XVI. fig. 2), show a complete mesh work of anastomosing 

 blood-vessels, which do not seem to be reduced to the size of 

 capillaries, since in the smallest twigs several blood-corpuscles 

 pass in column. A large volume of blood is thus carried 

 swiftly into the organ. In transverse section, moreover, it is 

 found that these vessels are arranged along the external mar- 

 gins of all the folds (PI. XVI. fig. 1, c,c), so that they are 

 in close contact with the fluid in the ovarian chamber. A 

 thin epithelial coat with connective or basement-tissue beneath 

 alone intervenes between them and the cavity. The walls of 

 these blood-vessels are somewhat thick. In specimens 

 examined immediately after the discharge of the young fishes 

 the vessels are remarkably large and conspicuous as well as 

 gorged with blood. While preserving in the main a longi- 

 tudinal direction, each trunk has connexions with the adja- 

 cent vessels at short intervals. The villous processes carrying 

 these vessels fill the ovarian chamber at this time (after 



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