In spite of the vast amount of literature recently devoted to different phases of the general subject of rickets, comparatively little attention has been paid to the age limit of its active manifestations. In the main, writers have confined their descriptions of rickets occurring in older children to the occasional picture of "late rickets," and not infrequently differentiation between late rickets and osteomalacia has been so imperfect as to leave the identity of a given case in doubt. Preliminary to any addition to the clinical data existing, a brief citation of representative expressions concerning rickets and osteomalacia is therefore expedient.
MacCallom1 stated that rickets usually begins at the sixth month, lasting sometimes for several years with remissions and final healing. Delafield and Prudden2 noted that the disease usually occurs in the first two years of life but may be seen as late as the twentieth year. Hess3