扬子鳄胚胎脊髓胸段的组织发生

用尼氏染色及Ｈａｇｇｑｖｉｓｔ染色法观察了２４例孵育３～６２天的扬子鳄胚胎的脊髓胸段组织发生过程。孵育第３天，脊髓横断面近圆形，中央管呈长椭圆形。第６天脊髓呈卵圆形，中央管呈窄而长的梭形，套层明显。第１２天，脊髓灰质的腹角明显，脊髓外周出现一薄层白质。第１８～３０天中，灰质腹角进一步扩大，背角逐渐形成。两侧背角不断向正中靠拢并合并，中央管缩小呈圆形。白质明显增厚并形成背索、侧索和腹索。第３０～６２

HISTOGENESIS OF THORACIC SPINAL CORD OF ALLIGATOR SINENSIS EMBRYO

Histogenesis of thoracic spinal cord of alligator sinensis was observed with Nissl and Haggqvist staining based upon 24 embryos aged from 3rd-62nd incubation day. At 3rd day of incubation, the transection of spinal cord was nearly round in shape, and the central canal, long elliptic. At 6th day, the spinal cord was ellipse-shaped, and the central canal, narrow and long shuttle-shaped. The mantle layer of spinal cord was visible. At 12nd day of incubation, the ventral horn of gray matter was visible, and a thin layer of white matter appeared around the spinal cord. During 18-30th days of incubation, the ventral horn of gray matter further enlarged, and the dorsal horn formed gradually. The central canal was narrowed to be round in shape because both sides of dorsal horns closed gradually toward the median line and merged. The white matter, which formed dorsal, lateral and ventral funiculi was now clearly got thich. During 30th-62nd day of incubation, the ventral median fissure deepened distinctly because both sides of ventral horns also closed toward the median. Neurons at the ventral and dorsal horns differentiated gradually and matured.