PROOBEDINaS OF THE SOCIETY. 295 



Dr. Ord described and figured on the black-board certain sym- 

 metrically-placed large nerve-fibres whicb be bad discovered in tbe 

 spinal cord of the pike, the axis-cylinders of these animals being of 

 enormous size, at least seven or eight times the diameter of the largest 

 axis-cylinder found in the human spinal cord, or so far as is known 

 in any of the higher mammalia. 



Mr. Stewart said that the presence of the large fibre described by 

 Dr. Ord with its proportionately large axis-cylinder was a matter of 

 considerable interest, and that he looked forward to Dr. Ord's further 

 investigations, so that its connections might be determined and data 

 derived for understanding its chief function. 



The President said they were greatly indebted to Dr. Ord for his 

 description and drawings, and expressed the hope that he would be 

 able to lay before them during the present session the results of his 

 further investigations so that they might be published in proper 

 form. 



Dr. Ord, in reply to a question as to the way in which he prepared 

 the cords referred to, said that they were partly prepared with strong 

 spirit, and partly with Miiller's fluid with a considerably long immer- 

 sion. For those that he was now preparing he used a bichromate of 

 ammonium solution. 



Mr. Crisp referred to the objection that had been raised to homo- 

 geneous-immersion objectives as regards their liability to be scratched 

 (see p. 264). 



Dr. Edmunds said that he had used homogeneous lenses from 

 their earliest introduction, and that the surfaces of the front lenses 

 were still as highly polished, and the objectives in fact in all respects 

 as perfect now as they were at first. 



Dr. A. S. Mercer's views as to stereoscopic vision with non- 

 stereoscopic binocular arrangements were explained by Mr. Crisp 

 (see p. 271). 



Mr. Stewart described and exhibited a gold-stained preparation 

 of the crop of a snail, showing the nerve-termination having occa- 

 sional large nerve-cells (in groups of rarely more than two) connected 

 with it. From these large fibres spring, and there were others much 

 smaller with groups of nerve-cells, from which again proceeded 

 fibres of exceeding minuteness, forming a dense intercommunication 

 with a few mostly elongated nerve-cells connected with them. The 

 latter was apparently the terminal nerve-plexus, and lay immediately 

 beneath the epithelial lining of the pharynx. 



The President said he was grateful to Mr. Stewart for so inte- 

 resting a demonstration, which opened up a field well deserving the 

 attention of some of the younger Fellows. 



Mr, Stewart said that he did not in these experiments recognize 

 the termination in the muscle-fibres, but that some of them do so 

 there was no doubt. 



