Royal Society. 271 



Dr. Wollaston proceeds to illustrate this statement of the dis- 

 tribution of the optic nerves, from that observed in those of 

 Fishes: in the Sturgeon the eyes are diametrically opposite each, 

 other, each on one side of the head, the left eye being entirely 

 supplied with nerves from the left thalamus of the brain, and the 

 right eye entirely from the right thalamus. The blindness above 

 described, Dr. W. remarks, does not appear to be rare, but is 

 seldom particularly noticed, like many other things, because it is 

 not understood. 



This very interesting paper concludes with a short section in 

 which Dr. Wollaston applies the sympathy of structure in the 

 eyes, indicated by the effects just noticed, to the explanation of 

 the long agitated question respecting the cause of single vision 

 with two eyes. Every point in each eye is supplied with a pair 

 of filaments from the same nerve, and the two eyes thus sympa- 

 thize with each other in every point : hence arises single vision ; 

 and hence also the reason why infants direct both eyes in a cor- 

 responding direction, instead of squinting. 



March 4. — A letter to the President was read, from Sir 

 E. Home, Bart. V.P.R.S. entitled Some curious Facts respecting 

 the IValrus and Seal, discovered in the Examination of Spe- 

 cimens brought home by the late Expeditions^ frbm the Polar 

 Circle. 



As the late various expeditions to the northern regions had 

 been planned, primarily, by the President and Council of the 

 Royal Society, Sir Everard Home wished to lay before the Society 

 some curious facts which he had ascertained in the examination 

 of some specimens brought home by them. This he was desirous 

 of doing before the officers who were to proceed on the new expe- 

 ditions should have left our coasts, in order that they might know 

 that their exertions were important to science in various respects, 

 besides the grand objects of their researches; and that they 

 might likewise know that the pickle or brine in which provisions 

 are preserved at sea is well adapted to the preservation of the 

 internal parts of animals, preserving them in a better state for 

 examination, dissection, and injection, than when they have been 

 long steeped in spirits. 



