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Part III. — Ninth Annual Report 
Scotland. The reason which led to the Conference being called was 
the falling off in the quantities of valuable flat-fish captured in the 
North Sea, and the desire to prevent this by preventing the capture and 
sale of immature fish. 
After two days' discussion, the following resolutions were carried : — 
* 1. That this Conference considers it desirable that an Official Inter- 
* national Conference of European Maritime Powers should be 
* held with the view of concluding a Convention for the 
* prohibition of the landing and sale of undersized flat-fish 
* within their respective jurisdictions.' 
' 2. That the National Sea Fisheries Protection Association be re- 
' quested to formulate a set of questions, with a view to 
' obtaining Scientific and Statistical information in relation to 
* undersized fish, and forward it to each delegate, in order 
' that he may submit it to his Government for adoption.' 
There was general agreement as to the utility of scientific investigations ; 
those recently made by the Scottish Fishery Board, particularly on the 
capture and destruction of immature fish, were specially commended. 
Since our last Report appeared, the Marine Biological Association of 
the United Kingdom have published two additional numbers of their 
Journal, and also a special work on the Common Sole, by Mr J. T. 
Cunningham, the naturalist to the Association. In this Treatise,"^ which 
is illustrated by eighteen beautiful plates, Mr Cunningham gives a very 
full account of the most valuable of sea-fishes. The treatise is divided 
i'.ito four parts : taxonomical, morphological, bionomical, and economical. 
The classification of the flat-fishes is discussed ; the history of the genus 
Solea given, and the British species described. In the morphological 
section, there are chapters on the osseous skeleton, the muscular system, 
the viscera and vascular system, the nervous system, the skin, &c., and 
a chapter on embryology. Mr Cnnningham points out that the testes 
in the adult sole are extraordinarily small in proportion to the size of 
the body, and are quite concealed by the viscera. In a specimen, one 
foot in length, the right testis was 13 mm. long, and the left 10 mm. 
Further, while in other flat-fishes the testes become enlarged, soft, and 
white in the breeding season, in the sole they only slightly enlarge, 
and do not become either soft or white. The small size and incon- 
spicuous character of the testes account for the statement so frequently 
made, that male soles are very rare. Mr Cnnningham says that, in 
reality, males are captured in greater numbers than females ; no figures 
are however given to show the numerical proportions. The sole, which 
feeds chiefly at night, appears to live principally upon annelids ; to 
some extent on ophiurids. A description is given of experiments made 
as to the chromatic changes in the skin of the sole ; the conclusion 
being that the changes depend on the quantity of light acting on the 
fish, not on the tint or texture of the ground on which it rests. In 
regard to the spawning of the sole, Mr Cunningham states that only 
a few ova are ripened at a time in a given female ; and that the spawning- 
time (in the neighbourhood of Plymouth) extends from the middle of 
February to the end of April, the greater number of fish spawning in 
March and the early part of April. Comparatively few ova of the 
sole were obtained by tow-netting (the largest number obtained at one 
time was six), and no larvae The next stage discovered was after 
metamorphosis, or * flattening'; the smallest were 12 to 15 mm. long, 
* ' A Treatise on the Common Sole {Solea valgaris), considered both ."as an 
* Organism and as a Commodity.' Plymouth. Published by the Association, 1890, 
