386 Mr. Hunter’s Qbfervations on the 
Bull or Horfe than any other animal : fome of it is very firm ; 
and about the breaft and belly it is mixed with tendon. 
Although the body and tail is compofed of a feries of bones con- 
nected together and moved as in fifh, yet it has its movements 
produced by long mufcles, with long tendons, which renders the 
body thicker, while the tail at its Idem is fmaller than that of 
any other fwimmer, whofe principal motion is the fame. Why 
this mode of applying the moving powers fhould not have 
been ufed in fifh, is probably not fo eafily anfwered ; but in 
fifh the mufcles of the body are of nearly the fame length as 
the vertebras. 
The deprefior mufcles of the tail, which are fimilar in fitu^- 
tion to the pfoae, make two very large ridges on the lower part 
of the cavity of the belly, riling much higher than the fpine, 
and the lower part of the aorta paffes between them. 
Thefe two large mufcles, inftead of being inferted into two 
extremities as in the quadruped, go to the tail, which may be. 
confidered in this order of animals as the two polterior extre- 
mities united into one. 
Their mufcles, a very Ihort time after death, lofe their 
fibrous ftrudlure, become as uniform in texture as clay or 
dough, and even fofter. This change is not from putrefaction, 
as they continue to be free from any offenfive Imell, and is molt; 
remarkable in the pfoae mufcles, and thofe of the back. 
Of the Confruffiion of the Tail. 
The mode in which the tail is conftrudted is, perhaps, as 
beautiful, as to the mechanifm, as any part of the animal. It 
is wholly compofed of three layers of tendinous fibres, co- 
vered by the common cutis and cuticle : two of thefe layers 
4 
are 
