24 THE COLLECTION OF FOSSIL VERTEBRATES 



parts of the skeleton different from those of their modern repre- 

 sentatives. 



Ahnost equally complete, although less familiar, is the series 

 illustrating the Ancestry of the Camel, which may be found on the 

 north side of the hall near the east end. These animals, like the 

 Horses, evolved from small and primitive ancestors to large and 

 highly specialized descendants, and then became extinct in their 

 former home, the broad and arid plains of western America, before 

 the advent of civilized man, but survived to modern times in other 

 parts of the world (Asia, Africa and South .Vmerica ) . Less com- 

 plete series are the skulls and skeletons illustrating the ancestors 

 of Titanotheres and the ancestors of Rhinoceroses. These are 

 ranged along the south side of the hall beginning at the entrance. 



All these series have been placed according to geological age. 

 The most ancient specimens, found in the lowest rock-strata, 

 and hence representing the earliest stage of evolution, are placed 

 first in the series. The most recent ones, found in the upper- 

 most rock-strata, and representing the final stage of evolution of 

 the race, are placed last. Arranging the species of a race from 

 each stratum in the order of the age of the strata, we find that 

 they show a regularly progressive change from the most ancient 

 to the most recent. At no point in a given series can we draw a 

 line and say : This is and that is not, a Horse — or a Camel — or a 

 Rhinoceros. The visitor, therefore, can demonstrate for himself 

 the evolution of the race of Horses or Camels or Rhinoceroses, 

 within certain limits. Of the evolution of Man we have no satis- 

 factory illustration from fossils. 



It should be observed that the evolution of a race consists 

 mainly in the adaptation of the structure of the animals to par- 

 ticular surroundings and habits of life. There is also a universal 

 progress in intelligence, the more ancient animals ha\-ing rela- 

 tively smaller brains than their successors. 



The water-color restorations by Charles R. Knight, done 

 under the immediate supcrx'ision fif Professor Osliorn, mainh' 

 Water-color based on complete skeletons exhibited in this hall, 

 Restora- show the probable appearance of the different extinct 

 tions. animals, according to our best judgment, as indicated 



by the characters of the skeleton, appearance of tlicir nearest 



