<正>本文对豆科树种刺槐(Robinia pseudoacacia)根瘤发育过程的外部形态(形状、大小、颜色)变化进行了定位观察,并对各不同发育时期的根瘤内部结构变化作了连续石蜡切片的观察。对它们之间关系进行了初步探讨。

This paper deals with a periodical observation on the nodulation of locust (Robinia pseudoaca-cia). The preparations of successive paraffin section are observed as well. The cortical parenchyma cells along the path of bacterial invasion beging to divide and the invaded cells increase in size as the bacteroids appear. The increased meristematic activity and cell enlargement of cortical cells result in the formation of the nodule which grows outward from the root cortex. At the same time differentiation of vascular tissues,both xylem and phloem, takes place in the nodule. The vascular tissues of the nodule are connected directly with those of the root. The shape of the nodule is governed by the extent and location of the meristem, which is the site of active cell division and tissue differentiation.