The development of different regions of the spinal cord of the developing chicken embryo under normal and experimental conditions. Acid phosphatase section histochemistry combined with ultramicrochemistry.

Sciatic section ws performed in chicken embryos of 8 and 10 days of incubation. They were sacrificed 4 dys later. Acid phosphatase (AcP) was determined with ultramicrochemical methods in several regions of the grey matter of the lumbar spinal cord. The necrosis of anterior horn cells was accompanied by a strong increase in AcP activity. Furthermore, a significant rise in AcP activity in the basal part of the contralateral posterior horn was observed. This rise was not paralleled by any obvious change in th morphology of this region.