13° BIOLOGY AND ITS MAKERS 



details, and they made it possible for the observations ai 

 discoveries of others to be understood and to take their place 

 in the great system of which he was the originator. The 

 effect of the last step was to direct the attention of naturalists 

 to species, and thereby to pave the way for the coming con- 

 sideration of their origin, a consideration which became such 

 a burning question in the last half of the nineteenth century. 



Reform of the Linn^ean System 



Necessity of Reform. — As indicated above, the classifica- 

 tion established by Linnaeus had grave defects; it was not 

 founded on a knowledge of the comparative structure of 

 animals and plants, but in many instances upon superficial 

 features that were not distinctive in determining their position 

 and relationships. His system was essentially an artificial 

 one, a convenient key for finding the names of animals and 

 plants, but doing violence to the natural arrangement of those 

 organisms. An illustration of this is seen in his classification 

 of plants into classes, mainly on the basis of the number of 

 stamens in the flower, and into orders according to the number 

 of pistils. Moreover, the true object of investigation was 

 obscured by the Linnaean system. The chief aim of bio- 

 logical study being to extend our knowledge of the structure, 

 development, and physiology of animals and plants as a 

 means of understanding more about their life, the arrange- 

 ment of animals and plants into groups should be the out- 

 come of such studies rather than an end in itself. 



It was necessary to follow different methods to bring 

 natural history back into the line of true progress. The first 

 modification of importance to the Linnaean system was that 

 of Cuvier, who proposed a grouping of animals based upon 

 a knowledge of their comparative anatomy. He declared 



