618 ' REPORT— 1889. 



9. On the larval and post-larval stages of the Sole and other Food-Fishes. 

 By Professor McIntosh, M.D., F.B.8. 



The peculiar structure of the ovum of the sole, which has also been described by 

 Raffaele and J. T. Cunninfjham, was alluded to at the commencement. It was 

 further mentioned how easily the ova had been hatched at St. Andrews, in con- 

 tradistinction to the difficulties hitherto experienced elsewhere. The remarkable 

 coloration of the larval sole is diagnostic. Both body and fins are minutely 

 speckled with stone-coloured pigment, so that it is very readily seen in the water. 

 As it gets older this hue vanishes, and a general ochreous tint takes its place. The 

 structure of the head, position of the eyes (both being visible from the front, and 

 used by the animal for anterior vision), structure of the fins and other parts, were 

 next examined. The changes in the position of the oil-globules during the earlier 

 stages of development and after absorption of the yolk were also noticed. It was 

 stated that the larval and post-larval soles were amongst the hardiest and most 

 active young fishes, and that no difiiculty would be experienced in increasing this 

 fish by artificial means. Amongst other forms the larval and post-larval sprat 

 were described, and the diflerences between this species and the herring indicated. 



10. Notes on new and rare Forms at the St. Andrews Marine Lahoratory. 

 By Professor McIntosh, M.D., F.B.S. 



A peculiar change occurring in Lesueuria vitrea (a form first clearly described 

 as British last year) was noted. This consists of the great enlargement in many 

 examples of the mouth-lobes, so that the general aspect resembles that of 

 Lesueuria hyboptera of Alex. Agassiz. For the first time a Heteropod {Atlanta) 

 was intimated as an inhabitant of the British seas ; Actinotrocha, the remarkable 

 larval stage of Phoronis (a borer in calcareous rocks, &c.) was mentioned as being 

 common in autumn, while the Arachnactis-stn^Q of Edivardsia, in contrast to the 

 condition in the Zetlandic waters, was rare and minute. The use of the various 

 nets (bottom, mid-water, and surface) systematically throughout the year in con- 

 nection with fisheries' work demonstrated the continued presence of many types 

 hitherto supposed to be occasional and rare visitants. 



Botanical Department. 



1. The Occurrence o/ Arenaria norvegica in Yorkshire. 

 By J. G. Baker, F.B.S. 



2. The Meristern of Ferns as a Study in Phytogeny. 

 By Professor F. O. Bower, F.L.S. 



The Structure of the Nucleus in Saprolegnia. 

 By Professor M. M. Hartog, D.Sc. 



4. Observations on the Structure of the Nuclei in Peronospora, and on their 

 behaviour during the formation of the Oosphere. By Harold W. T. 

 Wager. 



The various organs of peronospora parasitica, the mycelium, antheridia, oogonia, 

 and conidia, contain numerous deeply-staining nuclei, which in very thin sections, 

 obtained by means of a ribbon section-cutting microtome, and stained in a very 



