1 86 ELEMENTS OF SCIENCE 



do more than indicate what the various branches of such 

 a study are, and to briefly portray some of the most 

 elementary and indisputable facts which concern living 

 beings. For everything beyond this, students are re- 

 ferred to the many special treatises which exist on each 

 of the numerous sub-divisions of the study of living 

 creatures considered as one whole. 



The study of that living whole the science which 

 includes the study of all living things is termed biology, 

 while botany treats only of plants, and zoology exclusively 

 of animals. 



. The living creatures with which we are familiar, have 

 various active powers, while every animal or plant has a 

 certain structure of its own. The most casual observa- 

 tion suffices to show that a fowl, a lobster and an oyster, 

 a rose-tree, a Scotch fir, a mushroom and a sea-weed, 

 have each of them a structure more or less different from 

 that of each of the others. There is a science which 

 deals with obvious structural differences, namely ana- 

 tomy. That word, taken by itself, generally refers to the 

 study of the structure of the human body, while the 

 structure of other animals, compared therewith, is 

 spoken of as comparative anatomy. But plants have also 

 their anatomy, though their structures are much simpler 

 than that of most animals. 



The material frame of an animal or plant may soon 

 be seen to consist of different kinds of substances. Thus 

 a cat's body* will be found to consist of fur, skin, flesh, 

 nerves, bones, &c. Similarly, a tree, such as an elder, 

 will be seen to be made up of woody substance, solid and 



* Readers are referred to the author's work on the cat (John 

 Murray) as a complete introduction to all branches of the study 

 of living things. 



