340 SPARKS FROM A GEOLOGISTS HAMMER. 



Birds ; (b) From typical land saurians upward through 

 Iguanodon, Hadrosaurus, Cotnpsognathus and Brontozoilm 

 to Struthious Birds ; though in both these series (only 

 given in part) the types structurally consecutive are not 

 always chronologically ranged in the same order; (c) The 

 Camel series, ranging from Poebr other him through Prolo- 

 labis, Procamelus, Pliauchenia and Camelus to Auchenia; 

 (d) The Rhinoceros series, ranging from Trilopus through 

 Ccenopus Aphelops and Ceratorhinus to Rhinoceros; (e) The 

 Horse series, ranging from Eohippus, through Orohippus, 

 Epihippus, Mesohippus, Miohipptis, Protohippus, Pliohippus 

 to Equus, all these chronologically as well as systemat- 

 ically arranged. Also several other series quite fully 

 made out, such as those leading to the Elephant, the Hog, 

 the Deer and the Ox. 



7. The tendency of fresh discovery is continually to 

 fill up preexisting gaps. Serial successions are being 

 completed from year to year; connecting links are com- 

 ing to light; terms once thought misplaced are found, 

 through new discoveries, to be in proper successional 

 order. 



In this state of the facts it is perfectly legitimate to 

 forecast results. Induction has established a law from 

 which we may deduce anticipated results. We may reason 

 then from what we expect to know, as well as from what 

 we know. 



We anticipate, accordingly, that in the course of time 

 it will be shown that our earth has been the abode of 

 complete successions of animal types, leading backward 

 from each of our modern generic or family groups, by 

 ever converging lines, toward ancestral centers; and from 

 these centers, other lines pointing toward some common 



