Morphology is a branch of biology dealing with the study of the form and structure of organisms and their specific structural features. This includes aspects of the outward appearance (shape, structure, colour, pattern, size), i.e. external morphology (or eidonomy), as well as the form and structure of the internal parts like bones and organs, i.e. internal morphology (or anatomy). This is in contrast to physiology, which deals primarily with function. Morphology is a branch of life science dealing with the study of gross structure of an organism or taxon and its component parts. History The etymology of the word "morphology" is from the Ancient Greek (), meaning "form", and (), meaning "word, study, research". While the concept of form in biology, opposed to function, dates back to Aristotle (see Aristotle's biology), the field of morphology was developed by Johann Wolfgang von Goethe (1790) and independently by the German anatomist and physiologist Karl Friedrich Burdach (1800). Among other important theorists of morphology are Lorenz Oken, Georges Cuvier, Étienne Geoffroy Saint-Hilaire, Richard Owen, Karl Gegenbaur and Ernst Haeckel. In 1830, Cuvier and E.G.Saint-Hilaire engaged in a famous debate, which is said to exemplify the two major deviations in biological thinking at the time – whether animal structure was due to function or evolution. Divisions of morphology Comparative morphology is analysis of the patterns of the locus of structures within the body plan of an organism, and forms the basis of taxonomical categorization. Functional morphology is the study of the relationship between the structure and function of morphological features. Experimental morphology is the study of the effects of external factors upon the morphology of organisms under experimental conditions, such as the effect of genetic mutation. Anatomy is a "branch of morphology that deals with the structure of organisms". Molecular morphology is a rarely used term, usually referring to the superstructure of polymers such as fiber formation or to larger composite assemblies. The term is commonly not applied to the spatial structure of individual molecules. Gross morphology refers to the collective structures of an organism as a whole as a general description of the form and structure of an organism, taking into account all of its structures without specifying an individual structure. Morphology and classification Most taxa differ morphologically from other taxa. Typically, closely related taxa differ much less than more distantly related ones, but there are exceptions to this. Cryptic species are species