[Patterns in the spiral formations of insects]

Regular features of spirals of chitinous filaments of tracheas were investigated in 12 species of insects. All species studied were found to have mosaic heterochirality, i.e. portions of opposite directions of curling in the trachea system, and prevalence of rightness or leftness in them. The percentage correlation of rightness-leftness are characteristic of each species and may be considered as hereditary features. The degree of prevalence of the rightness or leftness in some species as well as the degree of chiral purity (according to this parameter) is not connected with the direction of curling. The tendency to chiral purity is distinctly seen in species with both the right and left curling. As for the problem of species formation, it should be admitted that the independence of the curling direction on the one hand, and the prevalence of its degree--and the degree of chiral purity--on the other hand, speaks in favor of different mechanisms of their development. It is also confirmed by the fact that the distribution of the curling direction is referred to the whole complex of species while the degree of prevalence of any kind of curling and the degree of chiral purity are distinctive individual characteristics and are developing as a result of the adaptation selection, in connection with other features of the given species. At the same time, in accordance with some scientists it may be supposed that the directions of curling is developing on the basis of molecular structures and are thought to be accidental. Regular features of curling of trachea formations are different depending on localization of organs. For example, the tracheas feeding the malpighian vessels form spirals curling around every malpighian vessel and always to the right. Neither the trachea, nor the vessels form spirals without being in contact.