The height and width of both the large plica and projection formed by the follicle-associated epithelium(FAE) enlarged gradually,the same as the lymphoid follicle area a.

• 结果:随日龄增长,腔上囊绝对质量逐渐增高;腔上囊生长指数21日龄达最高;黏膜大皱褶高、宽度、淋巴滤泡面积、皮质宽度均不断增加;小结相关上皮向腔面形成突起,并不断增高增宽。