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Lengths of the ossified diaphysis of the humerus and femur were measured in 50 fetuses ranging from 65 to 290 mm Crown-Rump length. A significant correlation was found between the diaphyseal length and the CR length. No appreciable difference was noted in diaphyseal lengths of the humerus and femur i n fetuses of 85 mm CR length or below. Various growth phases were observed. The difference i n length of the femur and humerus is due to a comparative slow growth of the humerus during the later period of prenatal life. Diaphyseal growth rates of the humerus and femur are 0.18 mm and 0.21 m m respectively for every 1 mm increase in CR length. Regression coefficients for the lengths of the ossified shaft of the humerus and femur are 5.35 and 5.00 respectively. With the help of these coefficients, CR length of the fetus was estimated within a range of k 1 5 mm. From the estimated CR length, age of the fetus was determined with the help of a standard age and size curve with reasonable accuracy.Study of the correlation between linear growth of long bones and the CR (CrownRump) length of the fetus assumes importance in medicolegal practice, since the correlation can be used to estimate the age of the fetus from its available long bones.Growth of long bones during prenatal life has been studied in detail (Nishizuka, '26; Streeter, '49; Felts, '54). Radiographic studies on the prenatal ossification of human long bones recording the ratio of the lengths of the ossified shaft relative to the corresponding CR length have been undertaken (Bade, '00; Halonen, '29; ORahilly and Meyer, '56). Various phases of linear growth of long bones have been reported (Depreux and Fontaine, '51 ; Moss et al., '55) and a linear correlation between diaphyseal length and fetal height has been observed (Smith, '39; Saettle, '51; Olivier and Pineau, '60). Recently, Gray and Gardner ('69) and Gardner and Gray ('70) in their reports on the prenatal development of the humerus and femur published tables showing the lengths of the ossified shaft and the corresponding CR length in fetal specimens of 37 to 342 mm CR length. AM, J. PHYS. ANTHROP.. 36: 165-168.In the present study the lengths of the ossified diaphysis of the humerus and femur were measured in fetal specimens of 65 to 290 mm CR length and a formula derived to estimate the age of the fetus based on the correlation of the diaphyseal growth with the CR length. MATERIALS AND METHODSWe studied 50 apparently normal fetuses, 30 male and 20 female, delivered by normal women and having a CR length ranging from 65 to 290 mm. The CR length was measured, after fixation of fetuses i n 10% formaline for four to six months, with a specially prepared osteometric board to the exactness of 1 mm. Values were verified by recording several times. The limbs were detached and placed in 5% KOH solution at room temperature for about two weeks. After thorough washing in running tap water, the humerus and femur were dissected out and cleaned. The cartilaginous ends were removed gently. The remaining ossified ...

In this study 13- to 14-day fetal thymic lobes were implanted within the anterior eye chambers in mice either with or without a syngeneic newborn sympathetic ganglion. It was observed after 6 weeks of implantation that the thymic lobes that grew with the ganglia had fewer lymphoid cells than their counterparts which were grown without the ganglia. The cells that developed within the thymic lobes were Thy-1- and peanut agglutinin-positive. The thymic lobes that grew with sympathetic ganglia also showed the presence of adrenergic nerves, perhaps due to reinnervation of the thymic grafts from the ganglia.

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