This thesis presents ways in which X-ray diffraction and polarised light microscopy have been used to quantify the arrangement of collagen fibrils in cartilage. The need for quantitative techniques is highlighted by a survey of published studies of articular cartilage, the limitations of previous techniques and the discrepancies between the results obtained using them being noted.

X-ray diffraction patterns obtained from moist, bulk tissue provide a detailed description of the arrangement of the collagen fibrils. The arrangement is characterised by the direction of preferred orientation of the fibrils and an orientation distribution function, which describes the probability of finding a collagen fibril at a given angle to the preferred direction. Using the results obtained, the technique of polarised light microscopy is quantified and measurements of the extinction angle and the birefringence of a section again yield a similar description of the collagen fibril network organisation.

These techniques are applied to articular cartilage and vertebral end plate. Tissues at various stages of aging and development have been studied and the surface of articular cartilage has been further investigated by phase contrast microscopy. The collagenous structure thus found is then related to the stresses that each tissue has to withstand during its normal function within the body. The conclusion drawn is that the arrangement of collagen fibrils is very well suited to withstand the tensile forces imposed upon each tissue.