Striations or bands of increased density in the diaphyses of bones of growing children have been described by several observers (Eliot, Souther and Park1; Miller and Rubell2; Weisse3; Hamperl4; Phemister5; Wegner,6 and others). These bands are usually found between the ages of 12 months and 5 years. They appear to result most frequently from a disturbance of growth.
In this instance the temporary zone of calcification situated in that part of the cartilage which is about to be replaced by the invading osteoblasts seems to become more heavily mineralized concurrently with the retardation of the rate of invasion of osteoblasts (a part of the general slowing of the growth processes). The calcium in this temporary zone is ordinarily resorbed as the cartilage is replaced by osteoid tissue, which in turn becomes calcified. The temporary zone of calcification, which has become overmineralized as a result