1 8 THE SCIENTIFIC EVIDENCES OF 



the specific points wherein it differs from these 

 animals are without significance as proving the 

 one type to be more highly organized than the 

 others. But of course in many cases, and espe- 

 cially in the cases of the larger divisions, it is often 

 possible to say — The members in this division 

 are more highly organized than are the members 

 in that division. Our system of classification 

 therefore may be likened to a tree, in which a 

 short trunk may be taken to represent the lowest 

 organisms which cannot properly be termed 

 either plants or animals. This short trunk 

 soon separates into two large trunks, one 

 of which represents the vegetable and the 

 other the animal kingdom. Each of these trunks 

 then gives off large branches signifying classes, 

 and these give off smaller, but more numerous 

 branches, signifying families, which ramify again 

 into orders, genera, and finally into the leaves, 

 which may be taken to represent species. Now, 



