,— Evidence demonstrating,that,configurations,of polymers,in the,amorphous state,are,unperturbed,by intermolecular interactions,with,neighboring,chains,is reviewed, with particular emphasis on recent results of neutron scattering by mixtures,of deuterated,and,protonated,species.,Extension,of this,technique,to larger,angles,than,those,required,for,determination,of the,radius,of gryration establishes,close,agreement,between,intersegnnt,correlations,in a polymer,chain in the,amorphous state and those within the isolated chain, even at distances as small,as bA. Neutron,scattering,studies,have,been,especially,useful,in discern— ing,the,nature,of the,molecular,morphology,at the,crystal—amorphous interface.,In both,polyethylene and isotactic polypropylene, adjacent re—entry is comparatively rare, contrary to models accepted in the past. Return of a given chain to a site of the,crystal,surface,somewhat,removed,from,its,point,of exit,must,occur,frequen— tly, however. These findings have important implications regarding the process of plastic,deformation,in seinicrystalline,polynrs.,Recent,studies,by Wignall,and,Wu confirm,that,local,nlting,of small,crystalline,regions,effectuates,the,process.