In spite of the complicated plurality of the present ways of thinking about speech and the prerequisites of speech, it is possible to say that the various ways of thinking could be placed somewhere between the end points the „absolute“ formalism and the „consistent“ functionalism with the distinct transitional zone in between. One can assume that the development tends from the formalism to the functionalism and this means the way of rising of the explanatory power of the theories. In order to make the process successful it is necessary to look for such formal means that are able to rationally express the knowledge of consistent functionalistic theories. If it were not for this fact, the way from the „absolute“ formalism to the „consistent“ functionalism would be the unwished way from the rationalism to non-rationalistic speculations, far away from the bounds of science. If we insisted on the petrification of the so far existed formalisms, in the name of the aimed grade of formalisation, it would mean to persist on the knowledge of speech on interest of the brilliant formal language exercises.
The review deals with the comprehensive analysis of ultraviolet-B (UV-B) induced alterations in photosynthetic processes of higher plants and possible protection mechanisms. Between two photosystems, photosystem 2 (PS2) is main target for UV- B radiation stress. Depending on the mode of treatment, the oxidising side of PS2 and reaction centres are mainly affected by UV-B treatment. As response to UV-B stress plants develop some inherent adaptive mechanisms which decide the extent of the overall damage.