6 



for the Centaurs, men mounted on horseback, and steering the horse vvith 

 the rein, as ships at sea are governed by the heim. 



This boat-like frame is decked over, or covered in, by the approaching 

 of the i'ibs above, and is closed by the spine or back-bone strongly con- 

 necting them ; the spine also is made to carry the head and neck, the 

 opposite extremity of it after forming the broad sacrum, for the use of the 

 pelvis and hind limbs is narrowed and diminished, tili lost in the pointed 

 termination of the tail, which in some animals becomes a sort of rudder: 

 the greyhound, in swift running and turning, appears to make great use 

 of it, and to be assisted by it ; that the analogy of the trunk to a boat holds 

 good in many circumstances, and if not in all, it will assist in conveying 

 to US a more familiär notion of the structure than could be otherwise 

 obtained. 



To this frame, and suspended to the underside of the back-bone, are 

 disposed the various viscera hanging into its cavity ; and what is remark- 

 able, the liver, the weightiest and most solid of these, takes its place 

 nearest the centre of gravity between the hind and fore limbs : the stomach 

 variable as to its dimensions and weight, being next to it j the kidneys, the 

 smallest and lightest of these viscera, are disposed in that part of the spine 

 where the greatest flexibility prevails about the middle of the loins. 



The great internal cavity of this trunk is divided into two unequal 

 Chambers or compartments, tlie ehest and abdomen, by the fleshy curtain 

 of the diaphragm transversely stretched across it, and directed obliquely 

 from the loins downwards to the point of the sternum, and having a broad 

 tendinous centre or disc ; its direction appears to be laid parallel to the 

 opening of the abdomen in its depending posterior part ; a third recess or 

 compartment is provided by the bones of the pelvis, though not separated 

 from the great cavity of the abdomen ; and the ehest is again divided lon- 

 gitudinally by a process or extension of the membranous lining of its 

 cavity the pleura, which septumor division is called the mediastinum ; both 

 the diaphragm and this are seen interestingly exhibited in the coloured 

 plate. 



In furtber sketching this exquisite piece of mechanism, we observe that 

 this boat-like trank is elevated from the ground on four columns, which 



are 



