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September 2, 1863. 



The President in the chair. 



In answer to a question from Mr. Sheafe, a statement was 

 made by Dr. B. J. Jeffries, of the Building Committee, rela 

 tive to the condition of the new Building. Dr. Jeffries thought 

 it would be ready in October. 



September 16, 1863. 



The President in the chair. 



A communication from Elliott Coues, of Mount Pleasant 

 Hospital, Washington, on the Osteology and Myology of Co- 

 lymbus, w^as received and referred to the Publishing Com- 

 mittee. 



Dr. J. Wyman gave an account of some observations which 

 he had recently made on an Amoeba. 



The species referred to appeared in some fibrlne, which had been 

 confined between two plates of glass, for the purpose of watching the 

 progress of its decomposition in water. The Amoebge were first no- 

 ticed as minute points, and gradually grew to full size, without any 

 obvious change of form or structure. As seen under the microscope, 

 they appeared to be made up of a spherical sarcodic mass, which was 

 structureless, and in which were imbedded numerous granules, from 

 which last, however, a portion of the circumference of the organism 

 was wholly free. Solid bodies, lodged in the interior, were seen to 

 be discharged at various points in the circumference, seeming to meet 

 with little or no obstruction, and yet no opening yf as discovered at any 

 point. When the body to be discharged came near the surface, the 

 sarcode was pushed out before it, becoming more and more prominent 

 outwards, and at length broke like a bubble, leaving the contained 

 body free. 



The Amceba, in one instance, underwent complete spontaneous di- 

 vision in five minutes ; first taking on the shape of a dumb-bell, then the 

 two principal masses receded from each other, the band which united 

 them became thinner, and finally broke, just as does the thread which 

 unites two viscid bodies when drawn apart, and two complete Amce- 

 ba3 were formed. In another instance, the division had become nearly 



