( 161 ) 

 PEOCEEDINGS OF SOCIETIES. 



Medical Microscopical Society, 



Friday, July 17, 1874. — Jabez Hogg, Esq., President, in the chair. 



Slin Grafting. — Mr. Golding Bird read a paper on the mode of 

 growth of the new epithelium after skin-grafting, or at the edge of a 

 skinning ulcer. Si)ecimens illustrative of the subject were exhibited. 

 A summary of the changes observed is as follows : — A prolongation of 

 the epithelium forming the rete mucosum of the adjoining skin, in a 

 horizontal direction over the surface of the neighbouring granulation 

 tissue, the vertically placed cells of the rete mucosum losing their 

 upright position and becoming more and more inclined till quite 

 horizontal ; the epithelial scales placed more superficially taking no 

 part in the process, but becoming shed ; so that the new epidermis 

 was only one-third the thickness of that of the skin from which it 

 had sprung. He ascribed the adhesion of the new ejudermis to the 

 underlying granulation tissue to the insertion of the former into the 

 most superficial layer of the latter, the intercellular material of which 

 may be seen becoming fibrillated (like the fibrin of blood clot), 

 coincidently with the growth onwards of the epithelium, the granula- 

 tion cells disajipearing in great numbers at the same time. He had 

 never yet been able to find the granulation cells becoming developed 

 into epithelium ; but he had seen a few of them lying between the 

 cells of the new epidermis. The granulation tissue beneath the 

 earliest formed epithelium was the fii'st to become developed into 

 fibrous tissue. 



Mr. Coupland thought the disappearance to the naked eye at times 

 of a graft, and the subsequent growth of epidermis at the spot grafted 

 some time after, was a proof of the development of eijithelium from 

 granulations. 



Mr. Schfifer referred to the observed transformation of white 

 blood-corjiuscles on the recently blistered surface in the frog. 



Mr. Golding Bii-d, in reply, denied that a graft that reappeared as 

 stated had ever in reality disappeared. He believed that the deepest 

 layer of epithelial cells was always left, though not visible to the 

 naked eye. 



Paccinian Corjfuscles. — Mr. Schafer gave an account of these bodies, 

 discussing generally the various opinions held regarding them. He 

 explained the various component parts, and held that the " core " was 

 the layer of protoplasm described by Eanvier as covering the medullary 

 sheath of the nerves. He has seen a nerve pass from one Paccinian 

 body to another. 



Dr. Pritchard asked if the Paccinian bodies in the cat's mesentery 

 were the same as in the skin ? In reply, Mr. Schafer stated he con- 

 sidered them identical. 



Mycetoma. — Microscopic specimens of the " Fungus-foot of India " 

 were exhibited by the President. 



