PROCEEDINGS 



BOSTON SOCIETY OF NATURAL HISTORY. 



TAKEN FKOM THE SOCIETY'S RECORDS. 



May 16, 1866. 

 The President in the chair. Twenty-five members present. 



Dr. B. Joy Jeffries made a communication on the Anat- 

 omy and Physiology of the Ciliary Muscle in Man. 



At a meeting of the Society in January, 1865, I made some re- 

 marks on the anatomy and pliysiology of the ciliary muscle in man, 

 and as recent investigations have seemed to confirm them, I shall take 

 the liberty of presenting these in support of my views. I said that I 

 followed others in considering that the ciliary muscle in man, by con- 

 tracting upon its origin slackened up the suspensory ligament, and 

 thus allowed the lens to become more convex, thereby accommodat- 

 ing the refractive media of the eye to the divergent rays of light from 

 near objects and focussing them on the retina. In placing together 

 the anatomical accounts of this muscle, I could not make out that the 

 muscular fibres known as Miiller's circular fibres, are a distinct mass 

 enabled to act together as a separate part of the whole muscle. In 

 this I am now further confirmed by the investigation of Meyer, from 

 whom I have roughly copied these drawings. From this I think it 

 will be seen that these circular fibres can in contracting but assist the 

 action of the meridional ones. 



PROCEEDINGS B. S. N. H.— VOL. XI. 1 OCTOBEK, 1866. 



