1878.] 



Prof. Pedler on Cobra Poison. 



17 



thin layer of the jelly-like mesoderm. The ectodermic covering con- 

 sists, except over the free end where the cells are simple and flattened, 

 of long columnar, ciliated cells, the fixed ends branching into delicate 

 fibres, which form a stratum underneath the epithelium. A similar 

 condition of the ectoderm is described as met with in two depressions 

 of the surface, one being situate above, and the other below, the litho- 

 cyst ; and the resemblance which the elongated epithelium cells with 

 the subjacent granular-looking, but in reality fibrous stratum, exhibits 

 to the developing central nervous structures in the vertebrate embryo 

 is pointed out. These parts, in fact, probably represent the first 

 beginnings — phylogenetically — of a central nervous system. Some of 

 the cells of the ectodermic covering of the lithocyst are pigmented, 

 and these cells are provided each with an excessively long and fine 

 (sensorial) filament instead of with vibratile cilia. 



The endodermic core of the lithocyst consists of a prolongation from 

 the nutritive canal of the margin, which at the terminal part of the 

 lithocyst is continued as a solid projection, the cells of which contain 

 calcareous crystals or otoliths. 



A small lithocyst is further described, in which the otolithic pro- 

 longation of the nutritive canal penetrated the ectodermic covering, 

 and projected freely into the surrounding medium. 



Reference is made to the observations of Haeckel upon the nervous 

 system of Geryonia and Cunina, and to a recently published preliminary 

 notice by Oscar and Richard Hertwig, of the structure of the nerve- 

 tracts and sense-organs in various other genera of Medusas. 



January 17, 1878. 



Sir JOSEPH HOOKER, K.C.S.I., President, in the Chair. 



The Presents received were laid on the table, and thanks ordered 

 for them. 



The following Papers were read : — 



I. " On Cobra Poison." By Alexander Pedler, F.C.S., Pro- 

 fessor of Chemistry in the Presidency College, Calcutta. 

 Communicated by Dr. Fraxelaxd, F.R.S., Professor of 

 Chemistry in the Royal School of Mines. Received No- 

 vember 1, 1877. 



On my arrival in India my attention was strongly directed to the 

 enormous number of deaths, annually resulting from the bites of 

 poisonous snakes. Statistics of the deaths from such causes are 



vol. xxvn. c 



