[Further studies of the theory of nervous decussations. I. The phylogenic organization of the optic chiasm].

We introduce in our theory on the biological significance of nervous crossings an hypothesis about phylogenetic origin of optic chiasma. This hypothesis admit a migration of 180 degrees of primitive eyes in ancestors of Chordates. This migration would have been the cause of the crossing of the optic nerves. We analyse the hypothesis by the mean of schemes and discuss it in relation with the old and the new hypothesis about the origin of Chordates from Annelids and respectively from Echinoderms. We present probationary signs from comparative embryology and comparative morphology.