evident, that if the cushion at these places be not kept in 

 a sufficiently elastic condition to guard the delicate membranes 

 of this important joint from being compressed between the 

 navicular bone and these horny projections, injury to the 

 joint must ensue, and unsoundness of the foot become 

 inevitable. 



Having seen the changes, that have occured to the fatty 

 frog of Fig. 1, we shall naturally be led to inquire, whether 

 the sensitive frog has fared any better ; to this end we must 

 first examine it in Fig. 2, where we shall find it distinctly 

 marked at g, and by tracing it over the frog stay, a, we shall 

 see, that it extends over the whole surface of the horny frog 

 between it and the fatty frog ; but we shall in vain look 

 for it in Fig. 1 ; the constantly increasing compression, it 

 has received between the gradually hardening cushion and 

 the horny frog, has by degrees so effectually caused its 

 absorption, that not a vestige of it remains, as is shown 

 by g. Fig. 1. 



The diminution, that has taken place in the horny fi"og 

 of Fig. 1, will be made sufficiently evident by a comparison 

 of the parts marked d and / with the same parts of Fig. 2. 



