PHILOSOPHICAL TRANSACTIONS, 



Part II, 1882. 



Contents. 



VII. On the Structure and Development of Lepidosteus. By F. M. Baxfottb, 

 LL.D., F.R.S., and W. 1S T . Pabkeb. 



VIII. On the Development of the Skull in Lepidosteus osseus. By William 

 Kitchen Pabkeb, F.R.S. 



IX. On the Vibrations of a Vortex Ring, and the Action upon each other of Two 

 Vortices in a Perfect Fluid. By J. J. Thomson, B.A. 



X. The Bakebian Lectfee. — Chemical Theory of Gunpowder. By H. Debus, 

 Ph.D., F.R.S. 



XI. On the Refraction of Plane Polarized Light at the Surface of a Uniaxal 

 Crystal. By R. T. Glazebeook, M.A. 



XII. On the Results of Recent Explorations of Erect Trees containing Animal 



Remains in the Coal-formation of Nova Scotia. By J. W. Dawson, 

 LL.D., F.R.S. 



XIII. Experiments to Determine the Value of the British Association Unit of Re- 



sistance in Absolute Measure. By Lord Ratleigh, F.R.S. 



XIV. On the Comparative Structure of the Brain in Rodents. By W. Bevan 



Lewis, L.R.C.P. (Lond.). 



Index to Part II. 



Price £2. 



Extra volume (vol. 168) containing the Reports of the Naturalists attached to the 

 Transit of Venus Expeditions. Price £3. 



Sold by Harrison and Sons. 



Separate copies of Papers in the Philosophical Transactions, commencing with 1875, 

 may be had of Triibner and Co., 57, Ludgate Hill. 



