LINNAEUS 65 



of Celsius Linnaeus conceived the ground-plan of the 

 system of classification by which he was to revolu- 

 tionize botanical science. The system, since modified 

 by the advance of knowledge, was based on external 

 resemblances. The great work of Linnaeus was construc- 

 tive, not interpretative ; and he lived in a period that 

 may be called the renaissance of science. 



Linnaeus' work was a great step forward, and his system 

 of classification was based on the reproductive organs 

 (stamens and pistils) of plants. The number of species 

 known to Linnaeus in 1753, when he published his Species 

 Plantarum, amounted only to 7300. The Linnaean 

 division of plants is into twenty -four classes, depending 

 on the number, position, relative proportion, and combina- 

 tion of the stamens ; and the first eleven classes are dis- 

 tinguished solely by the number of the stamens, such as 

 the monandria (one stamen), diandria (two stamens), 

 triandra (three stamens), etc. The twelfth and thirteenth 

 classes are characterized by the situation as well as number 

 of the stamens ; the fourteenth and fifteenth classes by 

 the number and relative proportion of the stamens ; from 

 the sixteenth to the nineteenth classes, flowers are dis- 

 tinguished by the combination of the stamens with each 

 other ; the twenty-first, twenty-second, and twenty-third 

 classes are characterized by the stamens and pistils being 

 in separate flowers ; and, finally, the twenty-fourth class, 



which comprises the Cryptogamia or flowerless plants 



5 



