164 THE LIVING WORLD. 



remain a larger number have become reduced to a 

 few unimportant representatives of orders which 

 in former times were abundant in number and diver- 

 sity of form. Some of the orders that are still left, it 

 is true, are perhaps more abundant, so far as number 

 of species is concerned, than any orders of the past, 

 but as a whole the fauna of to-day consists of rem- 

 nants of the past. 



Summary of the Last Two Chapters. 



We may compare the history of the whole animal 

 world to the growth of a giant tree. As members of 

 the human race our position is among the topmost 

 branches, and it is only by peeping down through the 

 foliage that we dimly get an idea of the rest of the 

 tree. The foliage is dense and our vision is obscured. 

 Absorbed in that which immediately surrounds us we 

 fail to see the size and magnificence of this tree of 

 life, and, indeed, not infrequently we are inclined to 

 believe that man stands alone, having nothing to do 

 with the rest of the tree. Only by shutting our eyes 

 to the dense foliage that surrounds us, and by study- 

 ing the past do we learn that mankind too is a mem- 

 ber of the same tree of life that has lived through the 

 ages and has suffered so much from the storms of 

 the centuries to make room for his final appearance. 



If we can imagine ourselves as removed from our 

 natural position among the branches and viewing 

 this tree of life in perspective from the distance, it 

 will appear something as follows. Its trunk is hid- 

 den from our view by the primeval mists of the early 

 ages, though its existence in the dim past can be in- 



