 The optic tract grows from the retina to the optic tectum , as dorsal and ventral are inverted in the anterior head region, the tracts grow at first to the ventral side  to meet in the midline to form a chiasma.
<coherence>  The optic tract grows from the retina to the optic tectum , as dorsal and ventral are inverted in the anterior head region, the tracts grow at first to the ventral side  to meet in the midline to form a chiasma.
 The optic tract grows from the retina to the optic tectum . Because dorsal and ventral are inverted in the anterior head region, the tracts grow at first to the ventral side to meet in the midline to form a chiasma.