Apparent [Sigma] hyperon decay events in a large emulsion stack of 240 9" x 12" pellicles have been classified into those judged to have occurred at rest and those in flight. Of 36 decay events at rest, 21 secondaries were observed to be protons of about 1675 microns range. Of the events decaying in flight, 23 were decays into protons and 46 were decays into near-minimum secondaries. Attempts have been made to trace the tracks of 35 of the lightly ionizing secondaries; the results of this effort are summarized in a table.

The basic information about the path of carbon in photosynthesis is reviewed, together with the methods that were used to discover it. This has led to the knowledge of what is required of the photochemical reaction in the form of chemical species. Attention is then directed to the structure of the photochemical apparatus itself insofar as it is viewable by electron microscopy, and some principles of ordered structure are devised for the types of molecules to be found in the chloroplasts. From the combination of these, a structure for the grana lamella is suggested and a mode of function proposed. Experimental test for this mode of function is underway; one method is to examine photoproduced unpaired electrons. This is discussed.