Abstract: Dorsi-connected Stylonychia mytilus (two normal cells connected on dorsal sides) can be obtained by artificial induction,I.e.,certain pattern of cutting operation.Results from protargol staining and scanning electron microscopy (SEM) revealed that in each ventral side of the two dorsi-connected component cells,there are ventral ciliatures corresponding to a normal S.mytilus.In most cases,on any side of dorsi-connected S.mytilus,there are 4 rows of dorsal bristles (DB) on the dorsal side of one component cell (arranged similar to lst to 4th DB rows in normal cell),while 2 DB rows (similarly arranged as 5th & 6th rows in normal cell),are on the dorsal side of the other component cell.It is observed that most of dorsi-connected S.mytilus are formed by the connection of two cells at their dorsal cortical region between their 4th & 5th DB rows.Also,there are cases of various forms of dorsal cortical connections.During asexual division,the morphogenesis of cortical ciliatures on two dorsi-connected cells are similar to that of normal S.mytilus.In both of them,various cortical ciliatures,such as adoral zone of membranelles (AZM),frontal,ventral & transverse cirri (FVTC),right marginal cirri (RMC),left marginal cirri (LMC),and DB,are developed synchronously.Thus,it is supposed not only the cortical development in the two dorsi-connected component cells are relatively independent,but,theres also certain mechanism contrplling their mutual coordination.During asexual reproduction,dorsi-connected S.mytilus are always in the processes of being regulated to normal cells.It is suggested that this is related to the "un-coordinated" tendencies toward opposite directions due to the pnesence of a whole set of locomotive organelles (especially,AZM) with normal structures and functions in each component cell of the dorsi-connected S.mytilus.