This study deals with certain quantitative relationships of the human hand—namely, the percentage of the volume constituted by such of its components as dermis (22 per cent), muscle (15 per cent), tendons (10 per cent), bone (37 per cent), and connective tissue (15 per cent) and the amount of the vascular bed located in those components.

In three of the 100 hands utilized in this study the weight and indirectly the volume of a plastic cast of the vascular spaces was determined. The vascular space constituted about 11.8 per cent of the volume of the three normal hands.

By dissecting the casts of the three hands, it was determined that the vascular bed was distributed as follows: within the connective tissue 47 per cent, within the bones 22 per cent, within the dermis 16 per cent, within the muscles 13 per cent, and within the tendons 2 per cent.

The distribution of small, medium-sized, and large vessels within each of the tissues of the hand was determined by teasing the cast apart and weighing separately the fragments with diameters less than 134 micra, with diameters between 134 and 536 micra, and with diameters larger than 536 micra. In such tissues as the dermis, muscles, periosteum, or bone, 75 to 85 per cent of the vascular bed is made up of vessels with a diameter less than 135 micra; whereas in these same tissues vessels with a diameter greater than 536 micra make up 4, 10, 10, and 5 per cent, respectively, of the vascular bed. Tissues with a low metabolic rate are supplied by fewer small vessels and transmit a disproportionate number of large vessels; thus, in tissues such as the dorsal connective tissue, the nerves, and the tendons, the small vessels constitute only 51, 67, and 50 per cent of the vascular bed, whereas the vessels larger than 536 micra make up 38, 5, and 41 per cent, respectively, of the vascular bed.