

* 





I 



Dublin Microscopical Club. m 211 



were endowed with the same remarkable power of rolling about 

 hither and thither. May these latter have been incipient gloeogenous 

 states of B. termo, and, though bound together, still retaining their 

 locomotive power ? If it be true that all Bacteria possess a flagcl- 

 lum at one or both poles, does each constituent cell of these Ccelas- 

 trum-like masses own a proper flagellum ? One could, Mr. Archer 

 thought, hardly look at the organisms now exhibited under the 

 microscope and not take them to be veritable Algae — Phycochro- 



maeeous Algse. 



Adventitious Ramifications of Callithamnion. — Dr. M'Xab drew 

 attention to an example of Callithamnion in which certain adven- 

 titious root-like dependent branches were given off from the axils of 

 the ordinary branches, and these, in place of remaining external, 

 passed inwards and became incorporated with the structure of the 

 stem of the alga, maintaining, however, still their individuality as 

 they passed thus downwards for a considerable distance! 



Artery from " tubercle" of Leprosy. — Mr. P. S. Abraham, M.A., 

 B.Sc, F.R.C.S., exhibited a section of an artery from a so-called 

 ^ " tubercle " of leprosy, showing obliteration of the lumen and enor- 

 mous thickening of the walls, which are closely studded with an 

 irregularly formed variously sized cellular growth. By the con- 



cases 



is in great measure made up. 



. Histology of Spinal Cord of Acanthias vidgaris. — Professor Mack- 

 intosh exhibited a cross section of the spinal cord of the Picked Dog- 

 fish (Acanthias vulgaris) taken from the dorsal region. The grey 

 matter was seen to be arranged in a somewhat T-shaped fashion; and 

 the axis-cylinders in the white substance were remarkable for their 

 size. The central canal was also particularly well defined. The 

 preparation was stained with blue-black and logwood, according to 

 Dr. Harvey's method. 



Section of Trap from Sutherlatulshire. — Prof. Hull, F.B.S., exhi- 

 bited a thin section of a sheet of trap which is found penetrating 

 the Lower-Silurian Limestone of Loch Assynt, in Sutherlandshire, 

 near Inchnadamff. It is a kind of diorite, consisting of short 

 crystals of hornblende, a little triclinic felspar, occasional small 

 grains of quartz, and of magnetite. The crystals of hornblende are 

 remarkable for the perfection of their crystalline form, and under 

 the polariscope present a vivid play of colours on rotating the ana- 

 lyzer. The author considered it unusual to find a hornblendic rock 

 associated with limestone in the manner of this intrusive sheet. 



Section of Reddish Felstone Porphyry. — Prof. Hull also exhibited 

 a section of reddish felstone porphyry from the neighbourhood of 

 Newtown Stewart, containing several crystals and groups of apatite, 

 showing various sections of the hexagonal prism according to the 

 plane of the section. The felsitic paste was seen with a £ ob- 



