of the Fishery Board for Scotland. 



243 



On the 4th April the blastopore had closed, with radiate streaks (Plate 

 IX. fig. 2), and Kiipffer's vesicle had formed. The muscle-plates are 

 delined and the notochord more evident. The yolk presents a faintly 

 granular aspect, it may be from indications of the future pigment- 

 corpuscles. The pectoral folds are large, and show many granules. 



The radiate strands from the pectoral region had become very distinct 

 on the 6th April, and black chromatophores had appeared over the yolk, 

 while indications of similar pigment were present along the body (Plate 

 IX. fig. 3). 



The black chromatophores had generally increased on the 7th April, 

 though there were variations in this respect, as shown in the figures of 

 this date (Plate IX. figs. 4 and 5). These eggs remained on the bottom 

 of the vessel, but retained vitality. 



Next day (8th) the sides of the embryo had a series of conspicuous 

 black chromatophores, these also being present over the yolk. The tip of 

 the tail now reached the head. The arrangement of the pigment thus 

 evidently differs from that in the cod, and foreshadows the more general 

 distribution of the chromatophores, so characteristic of the species in the 

 young condition. 



One hatched on the 9th April, but had died before Mr J. M. Anderson, 

 to whom I am indebted for sketches during my absence, could figure it. 

 Another, partially hatched, is figured in Plate IX. fig. 7 ; its vitality 

 having failed before complete extrusion occurred. The distinctive points 

 referred to are clearly seen in this advanced specimen. 



Mr Holt examined a ripe female, from the Great Fisher Bank at 

 Grimsby, on the 6th of February this year, but the eggs were all dead 

 and more or less altered, some being spherical, others ovoidal. 



It is remarkable that so few opportunities of seeing the fertilised ova of 

 this species have occurred, and yet it is a common form on both eastern 

 and western coasts. 



4. On a Small Egg resembling that of the Dab. 



For some years a small egg closely resembling that of the dab has 

 frequently been found at the surface in June. Its diameter, however, is 

 considerably smaller than that usually attributed to the dab, viz., from *6858 

 to "7620 mm., whereas the egg of the dab at St Andrews is generally from 

 •8382 to *8763 mm. Mr Cunningham gives "84 mm., and Professor Prince 

 and the author in the ' Researches ' stated it as *825 mm. The examina- 

 tion of these small eggs during development would seem to show that they 

 closely resemble the eggs of the dab. In order o to supplement what is 

 stated and figured in the ' Researches,' it may be well to give a brief out- 

 line of the conditions in these specimens, which last summer abounded at 

 the surface of the water both in St Andrews Bay and in Aberdeen Bay. 

 The early forms procured in the tow-nets had the embryo about half round 

 the yolk (Plate X. fig. 1), only a very faint yellowish tint being present. 

 Somewhat later (Plate X. fig. 2) the yellow pigment-spots form a distinct 

 double band, and the eggs are soon conspicuous in the water from its 

 further development. 



The larval lish (Plate X. fig. 3) resembles the dab most closely, having 

 only yellow pigment scattered on the head and in a double line along the 

 trunk. The larvae often iloat on the surface of the still water with the 

 yolk-sac uppermost. A thin strand connects the rectum with the edge of 

 the marginal fin, but there is no anus. A pair of sense-organs occur a 

 little in front of the vent, and three pairs behind. In one an ovoid 

 oleaginous mass moved freely in the yolk (Plate X. fig. 4), and a few 

 small oil-globules rested on this mass, as often seen on the oil-globules 

 of other species. They are delicate, the larvai perishing from elevation 



