Cilia in the head of hornets: form and function.

In the head of the Oriental hornet, beneath the cuticle, there are plaques of hair cells. These are distributed throughout the upper front part of the head; to wit: in the region of the vertex (i.e.

Are ciliary hair cells and photoreceptors components of a gravitic system of the hornet Vespa orientalis?

Social wasps, including the sub-family Vespinae, are social insects that build combs beneath the ground which are directed towards the gravitic pull of the earth, and this in dim light or complete darkness. On the inner side of the frons plate in social wasps there is a gravity sensing apparatus composed of static and dynamic nerve fibers, some of which connect between the frons plate and the brain. It is highly probable that the interaction between the fibers and the various structures in the head is responsible for the proprioceptive ability of hornets, including gravity detection.

Micromorphology of the dorsal ocelli of the Oriental hornet.

The development of vision in animals throughout evolution has been reviewed by Sir Stewart Duke-Elder, whose survey of the sense of sight ranges from lowly Crustaceans to mammals and man. According to Duke-Elder each ocellus is formed by the "fusion of two or more ocelli, each with its own retina and pigment cup". This process of 'ocellation' probably occurred independently in a number of phyla.

Non-coating fixation techniques or redundancy of conductive coating, low kV FE-SEM operation and combined SEM/TEM of biological tissues.

Non-coating fixation methods, in particular the tannic acid/arginine/osmium tetroxide procedure, are employed for a number of reasons on the guinea-pig organ of Corti hair cell stereocilia glycocalyx and the imprints of the stereocilia at the bottom side of the tectorial membrane, and on the rat and cat intestinal epithelial microvilli glycocalyx and mucus-producing goblet cells. These methods are used firstly to confirm that non-coating prepared specimens can be embedded for TEM observation at 60-100 kV without loss of detail information, and these images can be compared with cryo-FE-SEM images of the same structure/tissue. Secondly, they show that specimens treated according non-coating techniques become optimally preserved and electrically conductive, so that no external conductive coating is required.

A comparative study of thin coatings of Au/Pd, Pt and Cr produced by magnetron sputtering for FE-SEM.

Visualization of structural details of specimens in field emission scanning electron microscopy (FE-SEM) requires optimal conductivity. This paper reports on the differences in conductive layers of Au/Pd, Pt and Cr, with a thickness of 1.5–3.