i86 The Irish Naturalist. Nov. Dec, 



ROYAL ZOOLOGICAL SOCIETY. 



Recent gifts include a Squirrel from ■Mrs. Pierce, two Rabbits from 

 Miss R. Murray, a Silver Pheasant from Mr. W. Robertson, two Merlins 

 from Dr. Costello, a Kestrel from Mr. P. Walsh, and a Swan from Major 

 Cotton. A Diana Monkey and a pair of Guinea Pi ;s have been received 

 on deposit. 



DUBLIN MICROSCOPICAL CLUB. 



October 9. — The Club met at Leinster House. The President 

 (N. Colgan) exhibited the hairs or papillae of the seed of the Common 

 Groundsel [Senecio vulgaris) which when moistened display a remarkable 

 structure well described by \V. A. Leighton in vol. vi., p. 258, of the 

 Annals and Magazine of Natural History, 1841. While dry, these 

 short hairs have blunt undivided tips and lie adpressed to the seed, but 

 when a drop of water is applied they spread outwards, slightly bifurcate 

 and discharge from each of the lobes a long spiral thread which under a 

 high power is seen to be made up of several, at least six, strands. Issuing 

 at first with a rapid wriggling motion, these widely diverging threads 

 w^ave gently to and fro for a time and finally coming to rest surround 

 the moistened seed with a wide fringe of spiral threads, each from three 

 to four times as long as the hair from which it issues, and exceeding in 

 length the breadth of the seed. Hairs of this peculiar structure are not 

 characteristic of the genus Senecio, as one might expect them to be. They 

 do not occur either in S. Jacobaea or S. erucifolius, two very common 

 congeners of the Groundsel, though they are found in S. sylvaticus. Hairs 

 almost precisely similar in form and behaviour were detected by the 

 French botanist, M. Decaisne, so early as 1837 in Ruckeria, a genus of 

 Compositae native in the Cape and are fully described and figured b}'' him 

 in vol. xii., series ii., of the Annales des Sciences Naturelles. In this 

 paper he mentions other genera of Compositae as possessing seeds with 

 similar appendages. As for the function of this very curious and complex 

 hair structure, authorities generally regard it as a provision for anchoring 

 the seed and so aiding germination, this object being further promoted 

 by the emission of mucus along with the spiral threads. 



D. M'Ardle showed one of the foiiaceous group of Hepaticae, Scapania 

 umbrosa, Schrader, which he recently collected in Killakee demesne, Co. 

 Dublin, growing on decayed wood. It was collected in the same station 

 many years ago by the late Dr. D. Moore and reported in the Brit. Assoc. 

 Guide for 1878. It is a rare plant and it is interesting to know that it 

 flourishes there still, though reported from Kelly's Glen in 1896 ; these 

 are the only known Co. Dubhn records for the plant. This elegant minute 

 Scapania grows from ^ to | of an inch in height and is one of the prettiest 

 objects of the genus. The leaves are unequally bilobed to about the 

 middle, the antical lobe serrate in the upper half and beautifully guttulate 

 often papillose at the extremity ; the postical lobe is oval acute partly 



