125 



of San Francisco, in latitude nearly corresponding with that of 

 Ilichmond, Virginia. The Uri'a gryUe, whose extreme southern 

 breeding-point on tiie Atlantic is the Bay of Fundy, breeds also 

 near San Francisco. It may be, however, that the Eastern and 

 the Western birds will yet be found to be of different species. 

 Dr. Brewer believed that they would be. 



Dr. Pickering observed that the Song Sparrow lives all the 

 year at Philadelphia. As to the passage of birds across the 

 ocean, he could say that a flock of gulls kept company with the 

 ship, in which he crossed the Atlantic some time since, the whole 

 distance. 



Capt. Atwood remarked that, as to fishes, it is often the most 

 delicate, and those having the thiiniest skins, which are the last 

 to migrate. 



The President stated that he had recently an opportu- 

 nity, through the kindness of Dr. Bartlett, of New Bed- 

 ford, of dissecting the eye of a Sperm Whale, and the 

 parts surrounding it. 



On examining the region of the eye, an enormous development 

 of the muscles was inmiediately observed. The sclerotic coat 

 of the eye was very thick, and likewise formed a very thick 

 sheath around the optic nerve, imbedding the bloodvessels, 

 and almost as hard as bone. It was found, however, to contain 

 no ossific matter, and to be simply very dense fibrous tissue. 

 Behind the globe of the eye, and occupying a large space, was a 

 large venous plexus. The eyelids were thick, and the conjunctiva 

 folded back in such a manner as to permit the eye to recede in 

 the socket. The globe of the eye, together with the optic nerve, 

 w^eighed three and a lialf ounces. The powerful retractor muscle, 

 analogous to that of ruminants, weighed five and a half ounces. 

 The other muscles seemed only indirectly connected with the 

 globe, and their use seemed rather to be to open the lid than to 

 move the globe. The muscles which were attached to the lids 

 were of great size, and together weighed one and a half pounds. 

 The object of such muscular power he could not divine. The 

 vascular plexus distended would tend somewhat to force forward 

 the eye, and a sphincter muscle behind the eye would have a 



