RESUMO
17 young healthy rabbits weighing from 520 to 720 gins,ageing 38～48 postnatal days,were used for this study.Seven to fourteen days following spinal lesions at diffe- rent levels the animals were killed and serial transverse sections of thc brain stem were stained with thionin,the retrograde cell degenerations within the red nucleus were studied. An analysis of the chromatolysis indicates that the rubrospinal fibers are largely crossed and a few fibers to the cervical cord are uncrossed.Furthermore,a somatotopical localization exists within the contralateral red nucleus with respect to the rubrospinal tract,i.e.the cervical projections of the fibers system take origin from the dorsal part of the red nucleus almost throughout its whole extent,the thoracic projections from the ventral part of the caudal five-sixths of the red nucleus,and the lumbar projections from the centro-ventral part of the caudal third of the nucleus. It also indicates that all types of cells in the red nucleus,not only the large ones, give rise to the rubrospinal tract.The spinal porjections of this fiber tract may descend as far as the lumbar cord.
RESUMO
Forty human fetuses ranging from C-R length 72 mm (which corresponds to a developmental stage of the second week in the third month of the embryo) to fullterm were used to investigate the nutrient arteries of the femora using the dissection method and roentgenography. In comparison with adults, there are apparently more (P