RELATIONS. 1^ 



a falcon, or a kite, acts upon the animal fibre alone ; it will 

 not act upon seeds or grasses at all. On the other hand, 

 the conformation of the mouth of the sheep, or of the ox, is 

 suited for browsing upon herbage. Nothing about these 

 animals is fitted for the pursuit of living prey. Accord- 

 ingly it has been found by experiments, tried not many 

 years ago with perforated balls, that the gastric juice of 

 ruminating animals, such as the sheep and the ox, speedily 

 dissolves vegetables, but makes no impression upon animal 

 bodies. This accordancy is still more particular. The 

 gastric juice even of granivorous birds, will not act upon 

 the grain, whilst whole and entire. In performing the ex- 

 periment of digestion with the gastric juice in vessels, the 

 grain must be crushed and bruised, before it be submitted 

 to the menstruum ; that is to say, must undergo by art, with- 

 out the body, the preparatory action which the gizzard ex- 

 erts upon it within the body, or no digestion will take place. 

 So strict is the relation between the offices assigned to the 

 digestive organ ; between the mechanical operation, and 

 the chemical process. 



II. The relation of the kidneys to the bladder, and of 

 the ureters to both, i. e. of the secreting organ to the ves- 

 sel receiving the secreted liquor, and the pipe laid from one 



by the form of the teeth, he ascertains the nature of the stomach, the 

 length of the intestines, and all the peculiarities which mark a vegeta- 

 ble feeder. 



" Thus the whole parts of the animal system are so connected with 

 one another, that from one single bone or fragment of bone, be it of 

 the jaw, or of the spine, or of the extremity, a really accurate concep- 

 tion of the shape, motions, and habits of the animal, may be formed. 



" It will readily be understood that the same process of reasoning will 

 ascertain, from a small portion cf a skeleton, the existence of a car- 

 nivorous animal, or of a fowl, or of a bat, or of a lizard, or of a fish ; 

 and what a conviction is here brought home to us, of the extent of 

 that plan which adapts the members of everj^ creature to its proper 

 office, and yet exhibits a system extending through the whole range 

 of animated beings, whose motions are conducted by the operation of 

 muscles and bones ! 



" After all, this is but a part of the wonders disclosed through the 

 knowledge of a thing so despised as a fragment of bone. It carries us 

 into another science ; since the knowledge of the skeleton not only 

 teaches us the classification of creatures, now alive, but affords proofs 

 of the former existence of animated beings which are not now to be 

 found on the surface of the earth. We are thus led to an unexpected 

 conclusion from such premises; not merely the existence of an indi- 

 vidual animal, or race of animals ; but even the changes which the 

 globe itself has undergone in times before all existing records, and be- 

 fore the creation of human beings to inhabit the earth, are opened to 

 our contemplation. 



