The author, after referring to variations in the external form of the body in different individuals, and to the relations between external form and internal structure, proceeded to discuss the subject of variability in the different organic systems. He showed that internal structural variations conferred upon the individual characters as distinctive as any peculiarities in external configuration. It was argued that in the development of the individual a morphological specialisation occurs, both in internal structure and external form, so that each man's structural individuality is an expression of the sum of the individual variations of all the constituent parts of his frame.