On the basis of current knowledge on the structure and function of tonsils, in agreement with the author's concept on "panautoprotection" in the human body, an attempt at characterizing tonsils as analyzers of the immune system is made. It is suggested that adequate signals for these analyzers are high-molecular substances penetrating orally and nasally. It is emphasized that tonsillar specialization as immunological analyzers refers mainly to the structure of their surface epithelium, the latter being considered as a peripheral component of these analyzers. In evolution, antigen sensitive cells have developed, i.e., the so-called M (membranous) cells. The phenomenon of reticulation in adenoid and tonsillar epithelium is associated with the presence of M-cells in its surface. It is submitted that M-cells may produce immunologically relevant proteins, designated as tonsillopeptides, which can play a role in the formation of lymphoid cells with specific immunological competence. It is presumed also that all possible immunological interactions mediated by the whole range of cellular and humoral factors of immunity in cooperation with the autonomous nervous system may take place in tonsils.