GRADATION AMONG ANIMALS. 101 



Singly not that the connection between animals 

 is a material one ; for the same kind of relation 

 exists between lower and higher animals of one 

 type- or one class to-day, in their structural fea- 

 tures, in their embryological growth, and in their 

 geographical distribution, as we trace in their 

 order of succession in time ; and therefore, if 

 this kind of evidence proves that the later ani- 

 mals are the descendants of the earlier in any 

 genealogical sense, it should also prove that the 

 animals living in one part of the earth at present 

 grow out of animals living in another part, and 

 that the higher animals of one class as it exists 

 now are developed out of the lower ones. The 

 first of these propositions needs no refutation ; 

 and with regard to the second, all our investiga- 

 tions go to show that every being born into the 

 world to-day adheres to its individual law of life, 

 and though it passes through transient phases of 

 growth resembling other beings of its own kind, 

 never pauses at a lower stage of development, 

 or passes on to a higher condition than the one 

 it is bound to fill. 



If, then, this connection is not a material one, 

 what is it ? for that such a connection does ex- 

 ist throughout the Animal Kingdon, as intimate, 

 as continuous, as complex, as any series which the 

 development theorists have ever contended for, is 

 not to be denied. What can it be but an intel- 



