Some Regularities in Cellular and Subcellular Evolution of Structure, Chemism and Function of Sense Organs

Abstract

This chapter discusses cellular and subcellular evolution of structure, chemism, and function of sense organs. Irrespective of the remarkable resemblance in reaction of mobile antennae that are irritated by a specific stimulus, the substructural and cytochemical organization of receptory cells of sense organs has some principal distinctions as a result of their different functions. The distinctions expressed in the photoreceptor are determined by the presence, in the lamellae of its antennae, of molecules of a specific photosensitive substance, a carotenoid that is not only common for animals but also closely related to those in plants. These lamellae and the other structures of the photoreceptor also contain a series of nonspecific biologically-active chemical substances providing for some processes employed in the functioning of the cell as a whole. But in contrast to other receptory cells, these substances are located in the photoreceptor in a particular structural way. With some exceptions, a similar range of biologically active chemical substances acquires a varied structural localization in the process of development, depending on the specific features of the receptory cell. These facts and ideas show that changes in structure and chemism caused by changes in the function of receptory cells may be discovered at cellular and subcellular stages of their organization.