THE SCOPE OF BIOLOGY 19 



into sub-groups, the sciences which compose it may be enumer- 

 ated as follows: morphology, with its sub-groups: anatomy, 

 histology, taxonomy, distribution, structural embryology; and 

 physiology, with its sub-groups: physiology proper, functional 

 embryology, psychology, ecology, and sociology. (See reference 

 chart, p. 21.) 



MORPHOLOGY 



Morphology (Gr. morphe = form + -logia = discourse) is that 

 branch of biology which deals with the structure and form of 

 animals and plants. It may be divided into five sub-heads: 



1. Anatomy (Gr. ana = up + temnein = to cut) is the study 

 of all of the grosser structure of animals and plants, that can be 

 seen and dissected without the aid of the microscope. 



2. Histology (Gr. histos = a web + -logia) is the study of the 

 minute structure of animals and plants which is disclosed only 

 by the aid of the microscope. It is sometimes called microscopic 

 anatomy and deals chiefly with cell structure. 



3. Taxonomy (Gr. taxis = arrangement + nomos = law) is 

 the study of the relations of the organisms to each other and 

 includes the classification of species. 



4. Distribution is the study of the geographical distribution 

 of organisms at the present time, and also their distribution in 

 the past as disclosed by geology; to the latter study is given the 

 name paleontology. 



5. Embryology (Gr. embryon = an embryo + -logia) is the 

 study of the development of the organism from the egg to 

 the adult life. It is also called ontogeny (Gr. on (out) = be- 

 ing + -geneia = producing) in distinction from phylogeny (Gr. 

 phylon = race + -geneia = producing) , the development of the 

 race. 



PHYSIOLOGY 



Physiology (Gr. physis = nature + -logia) is the study of the 

 activities or functions of organisms. Its scope may be best 

 understood by its division into sub-heads: 



