of the Fishery Board for Scotland. 



239 



IV. — CONTRIBUTIONS TO THE LIFE - HISTORIES AND 

 DEVELOPMENT OF THE FOOD AND OTHER FISHES. 

 By Professor M'Intosh, M.D., LL.D., F.R.S., F.R.S.E., St Andrews 

 Marine Laboratory. (Plates VIII. -XII.) 



CONTENTS. 



PAGE 



1. On the Eggs and Lame of the Poor Cod, . . . .239 



2. On a Peculiar Example (Hybrid ?) of the Poor Cod, . . .241 



3. On the Eggs of the Green Cod or Saithe, .... 242 



4. On a Small Egg resembling that of the Dab, .... 243 



5. Further Remarks on the Eggs of the Halibut, .... 244 



6. On an unknown Egg measuring 1 '3335 mm., .... 244 



7. On an unknown Pelagic Egg, with u considerable perivitelline space, . 245 



8. On an unknown Egg measuring 12192 to 1*2952 mm., . . . 245 



9. On an unknown Larval Fish with Black Pigment, . . . 246 



10. On the Spawning Period of the Pollack, ..... 246 



11. Further Remarks on Young Pleuronectids, including the Turbot, Brill, 



and Topknot, ........ 246 



1. On the Eggs and Larvae of the Poor Cod (Gadus minutus). 



Raffaele * briefly alludes to the eggs and larvae of this species, which 

 seems to be one of the most ubiquitous gadoids — ranging from the genial 

 waters of the Mediterranean to the colder shores of the North Sea. He 

 remarks that the egg agrees in general structure with that of the cod, but 

 that the larva differs in the arrangement of the pigment. Marion, f again, 

 found a large number of ova in the Gulf of Marseilles — on the 7th March 

 — which he considered were those of the capelan (Gadus 'minutus), and 

 he gives a figure of the larva. Mr Cunningham,^: lastly, states that in 

 April he found this species ripe, the diameter of the ova 1*02 mm., and 

 the perivitelline space small. He did not hatch them. 



For several years the spawning of the poor cod has been under con- 

 sideration, but a more or less complete account has only been obtained 

 recently. In 1884 and 1885 many ripe females were seen, but no 

 ripe male was available at the same time. They were especially abun- 

 dant in June 1885. By the care and skill of a fisherman at St 

 Andrews (James Gourlay) numerous fertilised ova were brought from 

 the fishing-grounds near the Bell Rock in June last year, so that the 

 development could readily be followed. The nearly ripe ovarian egg 

 (Plate VIII. fig. 1) has as usual a denser capsule, and, moreover, is 

 wrinkled. Small vesicular masses are often seen on the surface of the 

 yolk. Ripe ova fertilised at 9 a.m. on the 6th June were in the multi- 

 celled condition at 545 p.m., with a perivitelline space (Plate VIII. fig. 2). 

 In diameter they varied from "039 inch to 0405 inch, or *9906 mm. 

 to 1*0287 mm. — sizes extending on both sides of the average given by 

 Mr Cunningham. The temperature at this time was elevated, and it 

 reached 70° on the 7th, so that development was quickened and consider- 

 able mortality ensued — indeed, the mere handling of the water containing 

 them under the microscope killed the embryos, which were outlined 



* Mittheilungen Zoolog. Stat. Neapol., viii. Bd., 1 Heft sep. abth., p. 36, tav. 1, 

 fig. 25, et tav. 2, figs. 20, 21, 1888. 



t Annates du Musee cVHist. Nat. de Marseille, ' Zoolog.,' iv. p. 118, pi. 2, Ag. 14. 

 X Jour. Mar. Biol. Assoc., N.S., vol. i., p. 375. 



