INTRODUCTION. 



THE SCOPE AND AIM OF PHYSIOLOGY AND ITS RELATION TO 

 ALLIED BRANCHES OF PHYSICAL SCIENCE. 



Physiology is the science of the vital phenomena of organs, or, briefly, 

 the study of life. In accordance with the classification of organisms 

 the following divisions are made, namely, Animal Physiology, Vegetable 

 Physiology, and the Physiology of the Lowest Forms of Life, which 

 occupy the boundary between animals and plants, the protists, micro- 

 organisms or microbes, and the elementary organisms or cells occupying 

 the same plane. It is the aim of physiology to establish these phe- 

 nomena, to determine their regularity and their causes, and to correlate 

 these with the general fundamental laws of natural science, especially 

 those of physics and chemistry. The relation of physiology to allied 

 branches of natural science is shown in the following scheme : 



BIOLOGY, 



The science of organized beings or organisms (animals, plants, protists, and ele- 

 mentary organisms). 



MORPHOLOGY. 



The study of the form of organisms. 



General Morphology. Special Morphology. 



The study of the formed elementary The study of the parts and organs 



constituents of organisms (Histology) : of organisms (Organ ology, Anatomy) : 



(a) Histology of plants. (a) Phytotomy. 



(b) Histology of animals. (b) Zootomy. 



PHYSIOLOGY. 



The study of the vital phenomena of organisms. 

 General Physiology. Special Physiology. 



The study of vital phenomena in The study of the functions of indi- 



general: vidual organs: 



(a) Of plants. (a) Of plants. 



(b) Of animals. (b) Of animals. 



EMBRYOLOGY. 



The study of the generation and development of organisms. 

 Morphologic division i . Developmental his- Physiologic division 



of the study of develop- tory of the individual of the study of develop- 



being (for instance, man) 

 from its germ, germinal 

 history (Ontogeny): 

 (a) In plants. 

 (6) In animals. 

 2. Developmental his- 

 tory of entire species of 

 organisms, from the low- 

 est forms of creation up- 

 ward, family history 

 (Phytogeny) : 



(a) In plants. 



(b) In animals. 



17 



ment, that is, the study of 

 the conformation at dif- 

 ferent stages of develop- 

 ment: 



(a) General. 



(6) Special. 



ment, that is, the study 

 of functional activity 

 during development: 



(a) General. 



(b) Special. 



