We studied the binding distribution of several lectins, Con A, DBA, UEA and WGA, in the embryonic development of the chick cerebellum between stages 18 to 45 of Hamburger and Hamilton. We observed a differential labeling (in intensity and distribution) in the migratory and cortical layers of the cerebellum anlage with these different lectins. The different distributions and modifications in the labeling pattern suggest intense variations of the glycoproteins and glycosaminoglycans in the extracellular matrix during development. These variations coincide with cellular and organizational phenomena in the migratory and cortical layers, and suggest compartmentalization of the Purkinje cell labeling.