LTNN^US AND NATURAL HISTORY 139 



The Organism. — In the time of Linnoeus the attention of 

 naturalists was mainly given to the organism as a whole. 

 Plants and animals were considered from the standpoint of 

 the organism — the external features wxre largely dealt with, 

 the habitat, the color, and the general appearance — features 

 which characterize the organism as a whole. Linnaeus and 

 Jussieu represent this phase of the work, and Buffon the 

 higher type of it. Modern studies in this line are like addi- 

 tion to the Systema Notiircp. 



Organs.— The first distinct advance came in investigating 

 animals and plants according to their structure. Instead 

 of the complete organism, the organs of which it is composed 

 became the chief subject of analysis. The organism w^as 

 dissected, the organs w^ere examined broadly, and those of 

 one kind of animal and plant compared Avith another. This 

 kind of comparative study centered in Cuvier, who, in the 

 early part of the nineteenth century, founded the science of 

 comparative anatomy of animals, and in Hofmeister, w^ho 

 examined the structure of plants on a basis of broad com- 

 parison. 



Tissues. — Bichat, the famous contemporary of Cuvier, 

 essayed a deeper level of analysis in directing attention to the 

 tissues that are combined to make up the organs. He dis- 

 tinguish ecf tw^enty-one kinds of tissues by combinations of 

 which the organs are com.posed. This step laid the founda- 

 tion for the science of histology, or minute anatomy. Bichat 

 called it general anatomy {Anatomie Geueraie, 1801). 



Cells. — Before long it was shown that tissues are not the 

 real units of structure, but that they are composed of micro- 

 scopic elements called cells. This level of analysis was not 

 reached until magnifying-lenses were greatly improved — 

 it was a product of a closer scrutiny of nature with improved 

 instrumicnts. The foundation of the w^ork, especially for 

 plants, had been laid by Leeuwenhoek, Malpighi, and Grew. 



