Microscopic anatomy of small intestine of Macaca radiata with special reference to gut associated lymphoid tissue.

The hitherto unreported microscopic anatomy of the small intestine of the bonnet monkey (M. radiata) was studied. There was a striking similarity in the general structure and cellular composition of the small intestine of the animal and that of humans. Of special interest was our observation of the occurrence of cells interspersed in the follicle associated epithelium which were morphologically similar to human M cells. These cells were pale, devoid of a brush border and frequently had lymphocytes apparently enclosed within them.