e=10;l=50;
modell:={x'[t]==y[t]-e (x[t]^3/3-x[t]),
         y'[t]==-x[t],
         x[0]==x0,
         y[0]==y0 };
x0=0;y0=2;
abb0=ParametricPlot[{x,e(x^3/3-x)},{x,-2.3,2.3},
     DisplayFunction->Identity,
     PlotStyle->{{Dashing[{0.01}]}},AxesLabel->{"x","y"}];
loesung=NDSolve[modell,{x,y},{t,0,l},MaxSteps->3000];
abb1=ParametricPlot[{x[t],y[t]}/.loesung,{t,0,l},
     DisplayFunction->Identity,
     PlotRange->All,PlotPoints->100,AxesLabel->{"x","y"}];
y0=5;
loesung=NDSolve[modell,{x,y},{t,0,l},MaxSteps->3000];
abb2=ParametricPlot[{x[t],y[t]}/.loesung,{t,0,l},
     DisplayFunction->Identity,
     PlotRange->All,PlotPoints->100,AxesLabel->{"x","y"}];
y0=11;
loesung=NDSolve[modell,{x,y},{t,0,l},MaxSteps->3000];
abb3=ParametricPlot[{x[t],y[t]}/.loesung,{t,0,l},
     DisplayFunction->Identity,
     PlotRange->All,PlotPoints->100,AxesLabel->{"x","y"}];
y0=14;
loesung=NDSolve[modell,{x,y},{t,0,l},MaxSteps->3000];
abb4=ParametricPlot[{x[t],y[t]}/.loesung,{t,0,l},
     DisplayFunction->Identity,
     PlotRange->All,PlotPoints->100,AxesLabel->{"x","y"}];
x0=0.1;y0=-6;
loesung=NDSolve[modell,{x,y},{t,0,l},MaxSteps->3000];
abb5=ParametricPlot[{x[t],y[t]}/.loesung,{t,0,l},
     DisplayFunction->Identity,
     PlotRange->All,PlotPoints->100,AxesLabel->{"x","y"}];
x0=0.3;y0=-5;
loesung=NDSolve[modell,{x,y},{t,0,l},MaxSteps->3000];
abb6=ParametricPlot[{x[t],y[t]}/.loesung,{t,0,l},
     DisplayFunction->Identity,
     PlotRange->All,PlotPoints->100,AxesLabel->{"x","y"}];
x0=1;
loesung=NDSolve[modell,{x,y},{t,0,l},MaxSteps->3000];
abb7=ParametricPlot[{x[t],y[t]}/.loesung,{t,0,l},
     DisplayFunction->Identity,
     PlotRange->All,PlotPoints->100,AxesLabel->{"x","y"}];
x0=2.5;
loesung=NDSolve[modell,{x,y},{t,0,l},MaxSteps->3000];
abb8=ParametricPlot[{x[t],y[t]}/.loesung,{t,0,l},
     DisplayFunction->Identity,
     PlotRange->All,PlotPoints->100,AxesLabel->{"x","y"}];
abb=Show[abb0,abb1,abb2,abb3,abb4,abb5,abb6,abb7,abb8,
DisplayFunction->$DisplayFunction,ImageSize->{400,300}];