60 THE MAIN CURRENTS OF ZOOLOGY 



the larger groups of animals will be helpful at this 

 point. 



Biological progress (outside the changes in classi- 

 fication) from Linnaeus to Darwin, although details 

 were greatly multiplied, proceeded by definite steps. 

 Linnaeus and his successors were concerned with the 

 organism as a whole, the external appearance, colors, 

 spots, the horns, the hoofs, etc. The next distinct 

 step was that taken by Cuvier and his school. In- 

 stead of the complete organism, the organs of which 

 it is composed became the chief subject of analysis. 

 The organism was dissected, the organs were exam- 

 ined and those of one kind of animal were compared 

 with another. This started the line of comparative 

 anatomy which played a much more important part 

 in the development of zoology than work of the 

 Linnaean type. After the organs were investigated 

 the tissues came under review and, then, with more 



