MEDICAL BOTANY 19 



value, so that Physiological Botany or Vegetable Physiology is brought 

 into service. 



Organography. — When structural botany has for its object merely the 

 determination of the organs as they exist, it becomes Organography. 



Organogeny or Morphology. — When such object is to determine the 

 development of organs through the transformations of others, as of a 

 petal from a leaf, or a tendril from a branch, it becomes Organogeny or 

 Morphology. 



Homologies and Analogies. — ^The ancestral organ and its developed 

 product are called Homologues of each other, and an Homology or 

 Affinity is said to exist between them. For example, the leaf of a plant, 

 and the petal of its flower, which we assume to have developed through 

 the modification of the leaf, are homologues of one another. When they 

 are only similar, without any genetic relationship, they are Analogues 

 of each other, and Analogy exists between them. Morphology might, 

 therefore, be defined as the study of homologies. 



Anthology and Carpology. — As classification has been based very 

 largely upon flower structure and fruit structure, the study of these, 

 respectively, has been dignified by the titles Anthology and Carpology. 



Phytography. — The description of plants in such manner that they 

 can be recognized therefrom is called Descriptive Botany or Phytog- 

 raphy. 



Other Departments. — Botany has also numerous departments depend- 

 ing upon the class of plants under study, as Phanerogamic Botany, the 

 botany of flowering plants; Cryptogamic Botany, that of flowerless 

 plants; Mycology, the study of fungi; Agrostology, the study of grasses. 



Agricultural Botany. — This is subdivided into a number of different 

 departments, such as Agrostology, or Graminology, the study of grasses 

 and of their culture; Horticulture, the study of garden plants and of 

 their culture; Floriculture, Pomology, and Forestry. Doubtless a very 

 large and important department will yet be established for the study 

 of the culture of medicinal plants. 



Medical Botany. — This term is self-explanatory as to its general 

 nature. In use, however, it should be more strictly regarded than is 

 customary. The term originally included all botany relating to medi- 

 cinal plants; but with the development of Pharmacy the greater portion 

 of what was once comprised in the former term has naturally and per- 

 manently established itself in the form of the separate department. 

 Pharmaceutical Botany. Medical Botany properly concerns itself with 

 the medicinal properties and active principles of plants, and the deter- 



