416 



usually, homogeneous aspect, which becomes altered during contrac- 

 tion by the supervention of highly i-efracting transverse ribs, which 

 grow thicker and more approximated as the process advances. 

 Meanwhile the " rod-shaped" nucleus appears to be pinched up by 

 the contracting fibre, till it assumes a slightly oval form, with the 

 longer diameter transversely placed. 



The author further remarks, that these properties of the constituent 

 elements of involuntary muscular fibre explain in a very beautiful 

 manner the extraordinary range of contractility which characterises 

 the hollow viscera. 



The folloA\ing Donations to the Library were announced : — 



Collection of Charts, published at the Hydrographic Office, London, 

 with relative Descriptions. — From the Admiralty. 



Results of Meteorological Observations, made at Sundry Academies 

 in the State of New York, from 1826 to 1850 inclusive. Com- 

 piled by F. B. Hough, M.D. 4to. — From the State of Neiu 

 York. 



List of Members and Report of Council, &c., of the Royal Institute 

 of Bi-itish Architects, 1856. 4to. — From the Institute. 



Annual Report of the Trustees of the New Yoi"k State Library, 

 1856. 8vo. From the State of Nevj York. 



List of Foreign Correspondents of the Smithsonian Institution, 

 1856. 8vo. — From the Institution. 



Map of Boundary between the United States and Mexico. By W. 

 H. Emory, U.S. Commissioner. — From the Smithsoniati Insti- 

 tution. 



Smithsonian Contributions to Knowledge. Vol. VIII. 4to. — 

 From the Institution. 



Nova Acta Academise Cgesarese Leopoldino-Carolinae Naturae 

 Curiosorum. Vol. XXV., Pars 2. 4to. — From the Academy. 



Mean Zenith Distances. Collection of all the Results of Observa- 

 tion of each star at Heerelogements-Berg, and Deduction of 

 Mean Zenith Distance, 1843. January 0. — From, the Royal 

 Observatory, Cape of Good Hope. 



Memoirs of the Royal Astronomical Society. Vol. XXIV. 4to. 

 — From the Society. 



Astronomical and Magnetical, and Meteorological Observations made 



