[The morphological and histochemical studies on the otolith membrane of the guinea-pig macula utriculi].

Morphological and histochemical observations were made of the otolith membrane of the macula utriculi in normal guineapigs. The influences of fixatives upon the structure of the otolith membrane were observed with several kinds of fixatives. The histochemical stainings were mainly applied to identify the acid mucopolysaccharides. Several of main findings were as follows: 1) The colloidal substance of the otolith membrane shows P.A.S. positive reaction, metachromatic reaction of toluidin blue and is stained with colloidal iron (after Rienhalt and Abul-Haj's method). And these chemical character is resistent to hyaluronidase. The author belibues from these observations that the colloidal substance of the otolith membrane consists mainly of the hyaluronidase resistent sulfomucopolysaccharides. 2) The cilia of the sensory cells is situated in the colloidal substance, however the special morphological relation between the cilia and the colloidal substance is not distinctly observed. 3) The otoliths are covered with the organic substance which shows the chemical characters as colloidal substance. Electron microscope shros the otolith itself consists of a number of electron dense fine granules of about 100A and the organic matrix with low density. 4) As a fivative, absolute alcohol seemed to be most suitable for morphological observation of the otolith membrane. The metamorphosis of the otolith in various pH of the fixatives can be attributed to the result of the chemical transfiguration of the matrix in the otolith and the organic substance which covers the otolith.