Column colors 2x speed (VIDEO) Northwestern University This video is under embargo. Please login to access this video. Caption Using cutting-edge techniques, Northwestern University researchers are the first to see cells moving into position in the developing hexagonal pattern of the fruit fly eye. Mechanical forces, not just chemical signals, are involved. Credit Please credit Northwestern University Usage Restrictions No restrictions License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.