6 o8 
Journal of Agricultural Research 
Vol. XI, No. n 
The characters selected for measurement include the following, which 
it was thought would best serve for the interpretation of size and con¬ 
formation: 
1. Weight (in pounds). 
2. Height at shoulder. 
3. Head length (sagittal length to horn ridge). 
4. Head width (transverse diameter at poll). 
5. Neck length (horn ridge to second dorsal vertebra). 
6. Trunk length (second dorsal vertebra to tail head). 
7. Chest depth (vertical diameter behind foreleg). 
8. Chest width (transverse diameter behind foreleg). 
9. Loin width (between fourth and fifth lumbar vertebra). 
10. Croup length (anterior point of sacrum to tail head). 
11. Foreleg length (elbow to ground). 
12. Hindleg length (stifle joint to ground). 
As nearly all of these measurements of conformation depend on skeletal 
dimensions, they are not materially influenced by variation in degree of 
flesh; so that, with the exception of depth and width of chest, the variation 
in measurements caused by variation in state of flesh is a negligible factor. 
As the whole flock was maintained under identical conditions of feed and 
management and was never kept in a high state of flesh, the chest measures 
give a uniform comparison and vary closely with variations of the skeleton 
of the chest. Measurements of purely quantitative flesh traits, such as 
body circumference at chest, neck circumference, and hindleg circum¬ 
ference, were taken but are not included here because they represent 
condition of flesh rather than size. Body size is determined by the 
quantitative development of structural characters which are measured 
as height, length of vertebral axis, depth and spread of frame. 
SIZE 
Because of a lack of sufficient distinction between size as expressed 
by weight (which is variable according to condition of flesh) and by struc¬ 
tural development (as a framework for carrying flesh) the term when 
applied to an animal as a whole may become confusing. 
Size, in the empirical sense, is expressed in various ways. In meat 
animals size is commonly expressed by weight; in draft oxen by chest 
circumference; and in horses by height at withers or weight, or both. 
From the geneticists' and breeders' point of view these terms are not 
only inapplicable, but are often misleading, as no single dimension is 
adequate to express size. 
Structurally, size is expressed in the summation of those dimensions 
that determine the limits of bulk—dimensions accordingly that are repre¬ 
sentative of the body type as regards length, depth, and width. 
Bulk, or volume, which is probably the best single criterion of size, is 
here for convenience of comparison measured by the form of two types of 
