of the Fishery Board for Scotland. 



133 



From the above observations it would appear that the mature eggs of the 

 John Dory are large, probably ranging between 2*5 and 2'8mm., that they 

 contain one or more oil-globules, and are demersal. The demersal nature 

 is indicated by the comparatively dense fibrous tissue of the stroma and 

 follicle, by the thickness of the capsule and the presence of a well-defined 

 double layer, by the character of the yolk, especially of the spherules, and 

 by the general hardness and resistance to pressure. In all these features 

 it contrasts with ovarian pelagic eggs. 



The condition of the eggs, as regards their degree of development and 

 the large empty cavity in the ovaries, points to the spawning period being 

 some months later than April. 



EXPLANATION OF PLATES. 

 Plate IL 



Fig. 1. — Ovaries of the Angler (Lophius piscatorius), 29 feet long, extracted in 

 February from a female 4 feet 2 inches in length, containing almost ripe eggs (shown 

 in fig. 13) ; a a, delicate membranous mesovarium ; 6, oviduct. Scale — half an inch 

 to a foot. (The distribution of the blood-vessels is to a large extent diagrammatic. ) 



Fig. 2. — Central part of the same, showing the junction of the two ovaries and 

 the oviduct. Part of the thin, barren wall of the ovary has been cut away to show 

 the inner surface of the ovigerous wall — the ovigerous pouches are represented as 

 circles in the gelatinous matrix ; the distribution of blood-vessels exactly shown. 

 Scale — 2 inches to a foot. 



Fig. 3. — Part of same ovary from which a piece of the barren wall has been 

 removed, showing the ovigerous pouches projecting into the gelatinous matrix. 

 Enlarged. 



Fig. 4. — Cross-section of the same ovary showing the germinal wall, with the 

 egg-pouches arranged in a single layer, and embedded in the matrix ; the barren 

 membraneous wall has been raised by a hook. (Slightly diagrammatic.) Scale — 6 

 inches to a foot. 



Fig. 4a. — The same, showing the junction of the ovigerous and non-ovigerous 

 walls. Enlarged. 



Fig. 5. — Nearly mature fresh egg of the Angler removed from the gelatinous 

 matrix, showing oil-globules and yolk-spherules. Enlarged. (The capsule is repre- 

 sented too thick.) 



Fig. 6. — Surface view of the epithelial mucin -secreting cells covering the outer 

 surface of the ovigerous pouches. Magnified. 



Fig. 7. — An ovigerous pouch containing a mature egg, torn across at its base and 

 removed. From a spirit preparation. Enlarged. 



Fig. 8. — Cross-section of part of an immature ovary of an Angler, 27 inches in 

 length, caught on 22nd November ; preserved in picro-sulphuric acid, and stained 

 with hsematoxylin and eosin, showing the junction of the barren and ovigerous walls, 

 the splitting of the latter, the protrusion into the pouches, &c. Magnified. 



Fig. 8(x. — Part of the barren wall of same, exhibiting the columnar epithelium. 

 Magnified. 



Fig. 9. — Cross-section of part of an immature ovary of an Angler, 30 inches long, 

 caught on 21st May, preserved in Perennyi's fluid ; showing same features as in 

 Fig. 8. Magnified. 



Fig. 10. — Small egg of Angler, in the fresh condition, measuring 0'02mm., show- 

 ing the clusters of oil-globules around the germinal vesicle. 



