CIIORIONIC VILLUS AND DECIDUA PAR lETATiIS

A large number of investigators have studied the general histology of the chorionic villus and decidua parietalis but few of them have been particularly concerned with the ccllular components which may be associated with the process of secretion. In 1916, de Kervily published two papers in which he described in considerable detail the cytology of the human chorionic villus. Many of his observations, especially those relating to secretion by the trophoblast, have failed to reccive general acceptance. Since that date, little attention has been given to the finer structure of the placenta. More extensive information concerning the cytolo,T of the placenta is desirable in view of the current interest in the physiology of this organ. It has been shown to play an important r6le in the regulation of the transfer of substances between the maternal and fetal blood streams and much accumulated evidence suggests that the placenta also acts as a gland of internal secretion. Hence, during the past several years we have carried on a cytological investigation of the human placenta, seeking to find structures within the villi and nearby decidua parietalis to which we might attribute an endocrine function. MATERIAL AND METHODS