In the course of the electron microscopic investigations of the problems relating to the crystalline character of the specimens, it is often desired to determine the correspondence between the inclined specimen at various glancing angles to the incident electron beam and the selective diffraction patterns of the same specimen area. By using the lamellar single micro-crystals of gold sol, having a variety of grancing angles to the electron beam, many kinds of cross-grating patterns were obtained and assorted into several classes. The aspect of the reciprocal lattice with extended intensity regions intersected by the reflection sphere were clarified for each of these classes respectively.
For the standard specimen of the selective diffraction method in a multiple stage electron microscope, the use of the lamellar single micro-crystals of gold has many advantages as the regularity of the cross-grating pattern has been clarified.

抄録全体を表示

Carp erythrocytes have been observed with a light microscope as well as an electron microscope in ultrathin sections revealing the following results: 1. The dense body, which appears in the cytoplasm, is connected with the cell membrane and nuclear membrane through a fine tube. 2. The nuclear membrane is composed of a porous external layer and a compact internal layer. 3. The chromatin granules 0.2-0.4μ in diameter and coiled threads are revealed in the nucleus. The former is stainable, but the latter has never been stained with Heidenhain's iron hematoxylin.

抄録全体を表示

1. The thread-like structure in the nucleolus of germ cells looks like a segment which has been cut through the tangled karyosome.
2. The existence of the double layers of nuclear membrane and their physiological difference have been confirmed during the metamorphosis of spermatids, when the nucleus is transformed into the sperm-head.
3. The exact process of formation of axial filaments and their sheaths has been traced, the former being derived from the mitochondria, the latter from the lipoid droplets and the round masses of unknown nature.
6. The mitochondria in the germ cells are variable in size and location during spermiogenesis.

抄録全体を表示

The preparations on which the present study is based were made from an albino rat's testis that was immersed in a solution of 1 per cent osmic tetroxide buffered at pH 7.4 with phosphate buffer for 40 minutes, dehydrated, embedded in n-butylmethacrylate and sectioned by a Spencer microtome at thickness ranging between 0.05 and 0.1μ.
The axial fiber of spermatozoa under development is composed of nine filaments arranged in a ring shape around a filament which is placed in the middle. In the axial fiber of the middle piece, the central filament is smaller than the other parts, but the nine peripheral filaments are thick and wedge-shaped. The axial fiber in the chief piece of tail tapers towards the peripheral part. The central filament is rather thick, but peripheral filaments become smaller demonstrating no wedge-shaped feature. It has been disclosed that each of the axial filaments is divided into parts. The axial fiber is enclosed by a ring with dense electron-density. Two nodures 0.1-0.15μ in diameter are situated symmetrically on the ring. Where the middle piece fades into the chief piece of tail two granules are found, through which the axial fiber runs. These granules suggest a longitudinal section of the so-called closing ring. The membrane of the middle piece is composed of at least three layers: the ieternal layer from the helical membrane, the middle layer from the caudal flap and the external layer from the cell membrane.

抄録全体を表示

Trypanosoma gambiense was studied with electron microscope, especially by means of ultra-thin sectioning.
The findings obtained may be summarized as follows:-
1. Trypanosoma gambiense is not so thin but considerably thick. Some of them hold the flagella in the stern as well as ahead.
2. Its cell wall, nucleus and nucleolus are clearly visible, being filled up with fine granules.
3. Many small bodies (perhap mitochondria) are noticed.
4. The main flagellum coated with sheath seems to be like as horsetail consisting of numerous filaments.

抄録全体を表示

The observation of the details in the stracture of the graphite grains in cast iron was carried out by means of cathodic vacuum etching. From electron micrographs, the detailed knowledges of the nature of the spheroidal graphite could be obtained.
Our experimental results on the crystallite structure and spheruliting process are described.

抄録全体を表示

Kaolin minerals derived from pumice tuff by weathering are mainly composed of hydrated halloysite. From the studies of X-ray powder reflection and d. t. a., these clay minerals have low crystallity and are mixed with allophane or gel-like substances. The shapes of these specimens are special and classified into the following types: (a) tubes, hexagonal plates and radial aggregates of plates, (b) tubes and redial aggregates of tubes, (c) polyhedral or spherical particles, (d) sugar-plum like grains, jutting out radially from the grains.
From this study the process in the growth from allophane or gel-like substance to hydrated halloysite can be postulated.
Furthermore, the presence of hexagonal plates on type (a) may be explained by the development of Bates' idea for a rolled shape on ordinal halloysite.

抄録全体を表示

This paper deals with a method of the two step positive replica newly developed by the auther using plastic material of high swelling character. By this method the time of completion of the replica was shorten. Over-more, it was found that the operation technique is easy and steady. And the resolution of same order as that ordinary replicas was obtained. Several applications for technical problems were shown. By these applications it was confirmed that this method is very suitable for the routin works.

抄録全体を表示

The effects of hydrazine sulphate added to the developer on the photographic plate for electron Microscopy are described. Exposure time can be reduced to a few tenths without remarkable deterioration of resolution.

抄録全体を表示