Yutaka Futaesaku

AN ANALYSIS OF THE HISTOCHEMICAL PROCEDURE FOR SODIUM ION DETECTION

Some aspects of the histochemical technique for the detection of sodium ions with potassium antimonate have been analyzed. When potassium antimonate is used for the detection of sodium ions the pH should not decrease below 7.2 during fixation. Potassium antimonate was also precipitated by ethanol used for dehydration, resulting in dilution of the water used as solvent. This should not be confused with the histochemical product. Precipitate may be formed with calcium ions and magnesium ions. Potassium phosphate buffer used to control the pH seems to inhibit the precipitation reaction of potassium antimonate with sodium ions; the nonbuffered fixative produces a good result at the electron microscopic level.

The fine structure of the spermatozoa of two species of Rhacophorus (arboreus, schlegelii): I. Phase-contrast microscope, scanning electron microscope, and cytochemical observations of the head piece☆

Green tree frogs, Rhacophorus arboreus and Rhacophorus schlegelii, living on the main island of Japan have spermatozoa in the form of a counterclockwise corkscrew composed of about 20 coils arranged in the shape of a cone. A head piece coiled loosely and tightly 5-6 times each. It was composed of two subcoils, one outside and the other inside. The outside subcoils composed the nuclear head, and the inside coils the acrosome. Following the head piece, a middle piece which had a mitochondrial sheath coiled 1 1/2 times. A tail piece which followed the middle piece coiled 3-10 times irregularly in 5-6 microns width with a 20- to 30-microns straight tail in length. There was a crystalline composed of 500-600 microtubules which surrounded a pair of cilial structures in the tail piece. The tannic acid-aldehyde-osmium tetroxide fixation method produced excellent electron density and good electron conductivity for scanning electron microscope observations.

Spines in the Hindgut of the Crayfish Procambarus Clarkii (Decapoda): Their Distribution and Correlation With Hindgut Muscles

ABSTRACT Spinal distribution and form in the hindgut lumen were observed in the crayfish Procambarus clarkii with the scanning electron microscope. The morphology of the circular and longitudinal muscles in the hindgut were observed by light microscopy. A relationship between spinal distribution and hindgut movement was suggested. The spines were finer, longer, and positioned closely together where the spongy reticular tissues and circular muscles had not developed. (1) At the anterior part of the hindgut, short thick spines were found on the tilelike cuticular surface of the anterior rectal pads. Density was about 2 spines per 10 µm2. The spiny cuticle, the surface of which was segmented into hexagonal or pentagonal tiles, covered the ridges of the rectal pads. A thin layer of circular muscles was observed at this region of the hindgut. (2) At the middle part of the hindgut, the spines became longer and finer as they approached the anus. Density was about 7.5 spines per 10 µm2. The thin layer of circular muscles remained unchanged. (3) At the posterior part of the hindgut, the spines were fine and short. Density was about 3 spines per 10 µm2. Four to 6 layers of thick, well-developed circular muscles were observed. Spine density was measured using NIH Image. All spines pointed in the direction of the anus. From these results, we suggest that the spines are closely related to differences in the physical movement in various sections of the hindgut. This is indicated by the thickness of the circular muscles and rectal pads in the respective regions.