i903i Proceedinp^s of Irish Societies, 135 



DUBLIN MICROSCOPICAL CLUB. 



March ii. — The Club met at Leinster House. 



Dr. ScHARFF exhibited a section through the ovary of a salmon, to 

 show the structure of the immature egg just before extrusion. He 

 pointed out that the large nucleus in the section was apparently 

 breaking up, and that the nucleoli were travelling towards the 

 periphery. He also made some remarks on the numerous vacuoles 

 found in the ^%%, on the egg membranes, and on the origin of the 

 yolk spherules. 



Mr. F. W. Moore exhibited sections through a peculiar swelling 

 found on the roots of an orchid imported from Madagascar. These 

 swellings appeared as nodules at intervals along the roots, and 

 seemed to be abnormal growths. The cells in places were large, and 

 the walls much thickened, the thickening material being interrupted 

 by canals at very regular intervals, giving the walls quite a beaded 

 appearance when viewed in cross section. 



Mr. Wirj.ouGHBV D. Dadk exhibited specimens representing two 

 genera of freshwater Polyzoa — viz., Loph&pus and Paludicclla. The latter 

 is remarkable as being the only freshwater Polyzoon belonging to the 

 order Gymnolcemata (throat unprotected by an epistome), which practi- 

 cally includes all the marine families. All the species of this order are 

 also characterised by a circular crown of tentacles, the absence of a 

 calyx or cup round the crown, and by not being reproduced by means of 

 " statoblasts." 



In Paludkella, however, the young buds are protected from the cold 

 of winter by becoming sealed up in horny sheaths (hybernacula), which 

 open on the return of spring, the terminal tubes splitting vertically and 

 releasing the young animals. 



Paludicella is of humble appearance, and a colony bears so strong a 

 resemblance to dead weed, that it might easily be overlooked. Lophopus 

 (the Folypa panache of its discoverer, Abraham Trembly) is a good 

 type of the order Phylactolcemata (throat protected by an epistome), 

 which is confined to fresh water. This epistome is co-extensive with 

 the crescentic or horse-shoe crown of tentacles, the latter being sur- 

 rounded at the base by a calyx. In this order also there is a curious 

 method of reproduction by " statoblasts,'" or winter eggs, which are 

 regarded as free buds, and not as ova. There is a division of opinion as 

 to whether Lophopus, like Crtstatel/Q, is locomotive. The exhibitor 

 had kept specimens for some time, and had never seen signs of such 

 power. 



Mr. M'ArdlE exhibited specimens, in fruit, of Tetraplodon Wormskioldii, 

 Lindb., and also dried specimens, which were collected b}- Mr. M. B. 

 Slater, of Malton, in peat moss swamps, top of Widdybank Fell, Upper 

 Teesdale, June loth, 1870, and placed in his herbarium as a robust form 

 of Tetraplodon mnioides, where it remained until its recent discovery in 

 the same locality by Messrs. Horrell and Jones [Journal of Botany, vol. xl., 

 p. 49, 1902). Along with being a beautiful microscopic object, on 



