402 



Part III. — Seventh Annual Report 



also made use of the species that are kept in the tanks at the Naples 

 Zoological Station, and was thus able to determine the eggs of various 

 species. 



The following are the conclusions of the author : — (1) Almost all the 

 important food fishes of the Gulf of Naples have eggs which either (and 

 generally) float at the surface, or are suspended at varying depths; (2) 

 the development of these eggs is very rapid, requiring from two to (rarely) 

 twelve days ; (3) eggs are found floating in the Gulf of Naples in all the 

 months of the year, but they are most abundant and represent a greater 

 variety of species in sirring and the beginning of summer; (4) the ova 

 of a given species are not spawned all at one time, but at various intervals 

 during a longer or shorter period ; (5) the ova are, for the most part, 

 spawned during the night ; (6) ' bottom' eggs belong, as a rule, to small 

 species of little value ; (7) beam trawling cannot have an injurious effect 

 on most fish eggs. A list is given of the floating eggs found in the gulf, 

 with the months when they were obtained. 



In relation to the above report, Dr Raffaele has published a long and 

 elaborate paper on 1 The Floating Ova and Larvae of Teleosteans of the 

 Gulf of Naples,'* which may be considered one of the most important 

 contributions to this department of marine research in recent years. In 

 the introductory portions Dr Raffaele reviews previous inquiries, and 

 discusses general points, such as the influence of temperature, &c, and 

 then deals seriatim with the embryos of many teleosteans. Probably its 

 chief interest for a fishery department consists in its description of the 

 ova and larval stages of the flat-fishes and of the clupeidas. Dr Raffaele 

 states that the ovum of the sole exhibits, as Mr Cunningham has also 

 pointed out, groups of minute fatty globules. These groups are scattered 

 on the surface of the vitellus, especially on the ventral side of the embryo. 

 There is a peripheral zone of the vitellus, which is vesicular in character. 

 Pigment is rather abundant both on the body, and on the vitellus, and 

 is black and an intense or a light yellow. In the larva the pigment be- 

 comes darker. In the turbot an abundant yellowish-brown pigment is 

 present in the ovum in large stellate cells over the whole body of the 

 embryo and on the vitellus. In the larva the yellowish pigment is 

 spread over the whole of the anterior part of the body, and there is a 

 large zone under the tail. The black pigment cells are few. The 

 clupeoid ova have a large pcrvitelline space, one oil globule, and the 

 nutritive vitellus is vesicular. The larvae are slender, the vitellus ellipsoid 

 and the oil drop is situated posteriorly. The paper is illustrated by five 

 large plates. 



NORWAY. 



A report on the work done in 1888 by Captain G. M. Dannevig, at 

 the well known fish hatching establishment at Plodevig near Arendal, was 

 published a few months ago. | It appears that besides the annual subsidy 

 given by the Norwegian Government to this hatchery, amadditional sum 

 to extend it has now been granted, large enough to enable operations 

 to be conducted on a much larger scale than hitherto. The mechanical 

 and natural difficulties which were first encountered when Mr Dannevig 

 began hatching operations were overcome by devising a method of keeping 

 the eggs in motion, and getting rid of the impurities that fouled the 

 hatching apparatus. 



* Mittlieilungcn ausd. Zool. Station zu Neapcl, Band viii. 1 Heft., pp. 1-84, 1888. 

 t Berctning om Flodevigens Udklmkningsanstalts Virksomhed, i Femaaret 1883- 

 1888. Arendal, 1889. 



