ON THE DEVELOPMENT OF THE COMMON FROG. 89 



The solution of this equation is 

 / dx\ z 2 





—t) =pi^]*{ i f^y(^ + »w-R 1 )F(a?)^ + c} 



If we suppose the motion to start from rest, the constant 

 will be o. Performing the integration, the result will be 



V 7rR 2 V / 



dx y / %g /x z , nx l x 4 



' -r + 2nx 



at" _^_V 7rK 2 V / 3/ z 4/ ? 



v- 



If we suppose the length of the tape to be infinite, the ve- 

 locity, after describing any finite space x, will be 



V¥- 



X. On the Development of the Common Frog. 

 By ThOxMas Alcock, M.D. 



Bead before the Microscopical and Natural -History Section, 

 February 13th and April 17th, 1882. 



With the intention of making a series of drawings of 

 frog-tadpoles in successive stages of development, I ob- 

 tained some spawn which the frogs were seen in the act of 

 depositing on the 3rd of April 1881; and on the 5th I 

 made my first observation, commencing a series which 

 extended to a hundred days, namely to the 1 2th of July. 

 Drawings were made almost daily ; and short descriptions 

 of the appearances presented were written at the same 



SER. III. VOL. VIII. H 



