4 build: definition and ontogeny. 



"stout" or "fleshy." In the present work the term "fleshy" is used, 

 despite its slight suggestion of muscular development merely, largely 

 because it begins with a different letter from slender. The word 

 "slender" will be used for the other extreme of build. It has been 

 found convenient to indicate those terms by their initial letters "S" 

 and "F" respectively. 



Our main problem is, in how far does this difference in build between 

 slender and fleshy persons depend on constitutional factors? 



Types of Variation in Build. 



Two types of variation in build have to be distinguished: (a) the 

 ontogenetic change in normal build during development with increas- 

 ing stature, and (b) the change in weight in adults of relatively 

 invariable stature. In type a, stature and other proportions are 

 rapidly changing, but in type b, stature remains constant, and, 

 throughout the race, stature does not differ as much in mature persons 

 as it does from birth to maturity. These two types follow different 

 laws and must be studied by different methods. Consequently they 

 are considered in distinct parts of the present paper. 



The Measurement of Build. 



It is now necessary to consider how build may best be expressed 

 quantitatively. The subject of the best index of build has been much 

 discussed, but without sufficiently differentiating between the two 

 types of variation in build, the ontogenetic and the adult. One of the 

 latest authors to consider the matter is Bardeen (1920, p. 486), who 

 mentions the desirability of recording the volume of the body as a 

 whole, notes its impracticability, and concludes that we may estimate 

 volume from weight. It may, however, be doubted if volume is really 

 involved in the popular notion of build. At least, it is equally prob- 

 able that the idea of build, as popularly conceived, is a relation of 

 transverse to vertical diameters. When I look at a man, or a photo- 

 graph of one as in plate 1, and think, "he is slender," it is because I 

 make a mental comparison of his breadth (of shoulders or chest) with 

 his height and find that his breadth in comparison with that of most 

 men I know of that height is small; or if he is stout the diameter of 

 the chest is large in relation to stature (plate 2). It seems probable 

 that breadth in relation to height gives the best expression of the 

 popular idea of build. By the use of this relation, build can be easily 

 expressed for any age, since chest circumference (which bears a nearly 

 constant relation to chest diameter) has been recorded for many per- 

 sons of all ages. 



Ontogenetic. — Since in so many children and young people the 

 stature and chest circumference have been measured, it is possible to 

 use these data in finding the law of normal ontogenetic changes in 



