|Cornsnake Morph Guide ®||Pattern Formation||Charles Pritzel|
The cells that create the pattern start out approximately where the brain is, and then migrate in two groups (one on the left side and one on the right side) down the center of the back, moving toward the tail and the nose. While migrating, they divide into subgroups and multiply.
These cells then migrate "downward" around the sides and eventually reach the center of the belly.
At this point in development, the two sides of the belly are not "connected" to each other, thus the migration does not go beyond the center line.
Once these groups of cells have reached their destination, they begin expanding to create their areas of color. For the first three groups, this area is filled with red pigment cells. The first group does not move very far, and ends up forming the dorsal saddles.