24 THE COLLECTION OF FOSSIL VERTEBRATES 
parts of the skeleton different from those of their modern repre- 
sentatives. 
Almost 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 America). 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 having rela- 
tively smaller brains than their successors. 
The water-color restorations by Charles R. Knight, done 
under the immediate supervision of Professor Osborn, mainly 
Water-color based on complete skeletons exhibited in this hall, 
Restora~ show the probable appearance of the different extinct 
LADS. animals, according to our best judgment, as indicated 
by the characters of the skeleton, appearance of their nearest 
