The oligosaccharidic content, distribution and changes of the glycoconjugates in the testis of the chick embryo, from the 8th day of incubation to hatching, were studied using a battery of seven HRP-conjugated lectins (DBA, SBA, PNA, ConA, WGA, LTA, and UEA I). Our findings showed that ConA and WGA appeared to characterize the spermatogonia during their differentiation, maturation, migration and meiosis. In the Sertoli cells, a change of localization of staining with ConA and WGA was revealed during the differentiation and maturation of these cells. The basal membrane was characterized by the reactivity with ConA and WGA from the early stages of incubation. ConA, WGA and PNA reacted with the endothelial cells of the testis for the whole period of incubation considered. Moreover, the interstitial cells, since their appearance, showed reactivity with ConA, WGA and PNA at the plasma membrane and the cytoplasm.