Excellent photographic experiments carried out by Bristol Groupl) give us ample knowledges about the nuclear interaction, since they visualize the nuclear interaction more directly and cover the wider range of energies than others. In order to facilitate our understanding on this problem, we must, first of all, build a picture or a model for cosmic-ray stars from this experiments. In other words, we ask the kind and the energy of their agents. We may tentatively classify the nucleons producing

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... he stars into A-, B-. and Ccomponent, according to their genetic relations and energies. 2l We see in what follows this classifica.tion is convenient and consistent for various cosmic'-ray phenomena. A-componont. This component has the