t922. • Irish Societies. 137 



IRISH SOCIETIES. 



DUBLIN MICROSCOPICAL CLUB. 



November 8. — The Club met at the Royal College of Surgeons. 



D. McArdle sliowecl the coiiidial stage of the Poi)lai-twig Fungus 

 Didyniusphaeria populiua. The specimens exhibited were taken from 

 the dead portion of the bark-wood on a shoot where infection took place ; 

 the numerous conidia are fusiform in shape with slightly curved ends 

 3-celled when matured. The affected tree Populus lasiocarpa shows the 

 first appearance of the disease by a dark brown spot on the side of a young 

 tAvig, which gradually develops quite around it, and marks the distance 

 the mycelium has ascended; as a result the young shoot and leaves become 

 discoloured and bend inwards and die. The buds below this part 



produce fresh shoots which in tlicir turn also become affected ; tlie lower 

 part of the tree becomes bushy owing to the production of suckers ; on 

 the destruction of the young shoots these also become aftected. On 

 the older branches large open rough wounds are seen sometimes exposing 

 the wood ; the infected spots join each other in time, quite encircling 

 or ringing the branch, the portion above the wound dying. 



H. A. Lafferty exhibited preparations of Phytophtlwra syriii^ac, a 

 fungus which has recently been recorded as causing a rot of apples in 

 this countr} . 



DUBLIN NATURALISTS' FIELD CLUB. 



May 6. — Excursion to the Zoological Gardens. — Tlie chief object 

 of tliis excursion, which was Avell attended, was to inspect and study the 

 recently established Irish Aquarium, which is being stocked for the special 

 purpose of facilitating the study of <jur nati\ e reptiles, batraciiians, small 

 fishes, and as many as can 'be conveniently kept together and exhibited 

 of the freshwater mollusca and aquatic insects and spiders. Mr. C. 11. 

 Bretherton, on whose shoulders the work of planning and stocking this 

 aquarium has hitherto almost entirely rested, acted as conductor a]id 

 gave an interesting account of the various inmates as they came into 

 view, hoping, as he explained, to enlist the activities of members of the 

 Club in collecting for the aquarium. After tea in the Haughton House 

 the members dispersed in groups to visit the \ arious animals. 



June 17.- — Excursion to Ireland's Eye. — Tlie party of 23 members 

 and friends met at Howth and crossed over to Ireland's Eye in motor 

 boats. An enjoyable two hours was spent on the island by the part\', 

 during which the scabird colonies were visited, including those of the 

 Razorbill, Puffin, Herring Gull and Kittiwake. A pair of Great Black- 

 backed Gulls were seen gilding majestically overhead and the nesting 

 hole of a Manx Slioarwaler was found under a, loclv'. ^[eadow Pipits 

 were numerous as were the Rock Pipits, many of whicli were singing 

 about the cliffs on the eastern side. Only twenty species of l)irds were 



