RECONSTITUTION IN DISARRANGED STENTORS 227 



one side (see Fig. 49). Also to be recalled in this connection is the 

 great confusion of shape when cell sectors are implanted hetero- 

 polar in stentors (see Fig. 54). Disarrangement of large areas of 

 ectoplasm therefore leads to much more confusion than mincing. 

 Reorientation of such areas may simply be more difficult, or their 

 polar " fields " may be so strong as to engender major conflicts 

 within the cell. 



The neatest and best studied disarrangement of the pattern of 

 Stentor is that in which the anterior half of the stentor is rotated 

 180° on the posterior (Tartar, 1956a; Uhlig, 1959). When coeruleus 

 is selected for this operation, the pigment stripes with their varying 

 widths can be used to identify the cortical patterns of the two halves 

 and to follow the changes which occur in them. 



The nature of these transformations of the striping depends in 

 part on whether and where the severed stripes may join. Using 

 these cases, stentors grafted heteropolar by the headless anterior 

 ends, and observations on minced animals, we can formulate 

 provisionally a rule for the union of lateral stripes. It will be 

 recalled that the complex fibrous structure Hes in the clear bands 

 and that the pigment stripes appear to be merely the spaces 

 between these which are filled in with the colored granules. Yet if 

 discontinuities in pigment stripes, appearing like the colorless 

 fission line, can be taken as a criterion that the fibers of the adjacent 

 clear bands are also discontinuous, then it seems that intimate 

 structural union between two sections of ectoplasm occurs only 

 when the abutting pigment stripes are of equal w^idth, approxi- 

 mately parallel, and homopolar. Thus in heteropolar grafts there 

 is no joining of pigment stripes even w^hen they are of equal width 

 (see Fig. 46E). In mincerates, as well as in parts of the normal 

 " ramifying zone " of Schuberg, it is indicated that pigment stripes 

 of equal widths do not join if they are at an angle to each other 

 (Fig. 63B). And in anterior-rotated-on-posterior grafts there is a 

 discontinuity where the wide stripes of one half abut the fine stripes 

 of the other, while in those places where stripes are of equal width 

 they join and become continuous (Fig. 66a). As will be noticed in 

 the figures, even though wide and narrow pigment stripes do not 

 join, there is the appearance of a strong attraction between the two. 

 Characteristically two fine stripes move so as to subtend one wide 

 stripe, although a non-pigmented line continues to separate them. 



