The Mammals 



aiding its creatures, has chosen the plan of adaptation rather 

 than that of extinction. 



The fossil remains of the earliest known mammals date 

 back to a period approximating 10,000,000 years ago. A 

 comparison of all the mammal forms leads to the conclusion 

 that all the orders of this class have sprung from a com- 

 mon ancestor. After this class had arisen above the preced- 

 ing and lower class of reptiles, they began to increase rap- 

 idly and to disburse from the original home of the parent 

 ancestors. Some took one road and some another. These 

 roads lead to the uttermost parts of the world. In travel- 

 ing these roads, they were led into new conditions and new 

 surroundings which called for a change in their habits of 

 living. Some progressed and some did not. A multitude of 

 cooperating conditions extending over millions of years 

 developed new species. All of the various orders have been 

 forced by circumstances to pass through many changes. 

 These various changes are more numerous and more notice- 

 able in the active and ascending orders. These orders are 

 constantly reaching out and upward. In this ascent, they 

 have been punished for their mistakes and rewarded for their 

 progress. The brain has gradually increased in size until 

 the species possessing the largest brain now has dominion 

 over all the world and its creatures. Through its functions, 

 the Plan of Creation and the relation of all things to each 

 other are now being revealed to the animal that has reached 

 the topmost branch in the tree of animal life as a reward 

 for its efforts. 



[233] 



