The stroma-cells have larg e numbers of dictyosomes and endoplasmic reticulums with simple structure,and mo st of the hemoblasts are granulate.

• 电子显微镜下，内皮细胞非核部分有伸向盲腔的突起，基质细胞中的高尔基体和内质网数量多、结构简单，血细胞大多为颗粒细胞。