[Ultrastructural characteristics of the simple eyes of the louse Pediculus humanus corporis].

The simple eye of the human louse consists of two apparatuses: dioptric and light sensitive. The dioptric apparatus contains only a biconvex lens, which represents local thickening of the cuticle. The eye lacks the crystal cone (Semper cells) and special pigment cells.

[Spectral sensitivity of the visual cells of the complex eye of Blatta orientalis].

Intracellular recordings were made from single photoreceptors of the frontal part in the compound eye of the cockroach Blatta orientalis. Two spectral types of cells were revealed: UV-receptors with lambda max = 361 +/- 8 nm and green-receptors with lambda max = 503 +/- 12 nm. Spectral curve of the whole eye measured by ERG had two peaks (at lambda = 350-370 and 500 nm) and minimum in the range of 400-430 nm.

[Similarity in the behavior of insects and vertebrates in solving difficult visual tasks].

Field experiments on elaboration of conditioned differentiation reflex in melliferous bees led the authors to the conclusion on convergent similarity of some characteristics of insects' and vertebrates' behaviour while solving difficult visual tasks. The similarity is expressed in phenomena of 1. "unlearning", or transition to choices at random, during repetitive difficult differentiations; 2.

[Identification of "slow" cells in insects eyes].

Responses of "slow" cells of the compound eye of grasshopper to equal-energetic flashes of monochromatic light of different wavelengths were recorded by intracellular microelectrode. Majority of cells had the curve of spectral efficiency of 540 nm. This curve coincided practically with the curve of spectral efficiency measured with ERG.