392 
Part III. — Ninth Annual Report 
1 inch to over 2 J inches. This number of the Journal also contains a 
report by Mr G. C. Bourne on the Surface Collections made in the North 
Sea and West of Scotland by Mr W. T. Greenfell, the superintendent of 
the Mission to Deep-Sea Fishermen ; Notes on the Hydroids of Plymouth, 
by Mr Bourne; a complete List of the Opisthobranchiate Mollusca found 
at Plymouth, by Mr W. Garstang, with interesting observations on their 
mori)hology, colours, and natural history ; and notes on the herring, long- 
line, and pilchard fisheries of Plymouth during the winter 1889-90, by 
Mr W. Eiach. In Mr Bourne's paper on the Tow-Net Collections made 
in the North Sea, it is mentioned that an abundance of Teleostean ova 
and larvae, in different stages of (levelo[)raent, were obtained in February 
and March, at distances of from 30 to 60 miles from land. A consider- 
able proportion of the ova are ascribed to the plaice, and the greater 
number of the nev/ly-hatched larvae were Pleuronectids. Larval herrings 
were obtained at 50 miles from land. A new Copepod, Hersiliodes 
CanuensiSf is described. 
In the last number of the Journal * the Director states that the services 
of Mr H. N. Dickson, F.R.S.E., have been secured in connection with the 
marine physical observations, which will in future be taken systematically 
in the Channel and in the harbours and estuaries in the neighbourhood. 
Experiments are also being conducted at Plymouth by Mr Hughes as to 
the production of artificial bait. This number contains papers on the 
following subjects : — 'The Plymouth Mackerel Fishery of 1889-90, from 
' Data collected by Mr Wm. Roach,' by Mr Calderwood ; * The Reproduction 
' and Development of the Conger,' V)y Mr J. T. Cunningham ; 'The Head 
* Kidney of Teleosteans,' by Mr Calderwood; 'The Tunicata of Plymouth,' by 
Mr Walter Garstang ; 'Some Larval Stages of Fishes,' by Mr Cunningham. 
In his paper 'On the Reproduction and Development of the Conger, 
Mr Cunningham, after reviewing previous observations on sexually 
mature specimens, gives an account of his own researches on the subject 
since 1887. A few nearly but not quite ripe ova were squeezed from a 
female on July 24th. They were chalk-white, opaque, had no separate 
oil globules, and the egg-membrane was everywhere in close contact with 
the vitellus. The eggs sank in sea-water ("density 1-027). An hour 
after extrusion a perivitelline space had developed, but the vitellus 
remained opaque, and there was no indication of blastodisc. In this con- 
dition the diameter was 1'6 mm. Attempts at fertilisation with ripe milt 
failed. The females are much larger and more numerous than the males 
(23toll).t 
Mr Cunningham concludes from his observations that the conger dies 
after spawning, and that the spawning extends over several months — from 
about April to October — or even throughout the year. Mr Cunningham 
discusses what is know or surmised regarding the ova of the conger after 
they are shed, and the larva. He considers that Ratfaele's observations 
at Naples have all but proved that the ova of the Muraenidae are pelagic, 
and that one of the eggs described by that naturalist is probably that of 
Conger vulgaris. 
In the fourth volume of the Proceedings of the Liverpool Biological 
Society Professor Herdman gives an account of the researches carried on 
* Journal of the Marine Biological Association of the United Kingdom, New Ser., 
vol. ii. No. 1, May 1891. 
+ In my paper on the ' Comparative Fecundity of Sea Fish ' {vide p. 243), I have 
shown that among fish producing isolated pelagic ova there is nearly always a 
preponderance in numbers and size of females, and that among fish with demersal 
ova shed rapidly thp males are more numerous (Salmon, Cyclopterus, Anxirrhichas), 
or about equal in numbers (herring, sand-eel). This supports Mr Cunningham's 
opinion that the ovum of the conger is buoyant. 
