Differential expressions: Key experiments in developmental biology

From somites to thalidomide / Jay Lash

Life cycles: lessons from the cellular slime mold / John Tyler Bonner

Pattern formation in the vertebrate limb / John W. Saunders, Jr.

Homeosis in the fly / Walter Gehring

Chimeric grafts: following the pathways of migrating cells / Nicole le Douarin

Primary induction the double-gradient hypothesis / Lauri Saxen.