a=100;
c=0.3;
p:=Module[{},modell={x'[t]==c x[t] (1-x[t]/a)-x[t]^2/(1+x[t]^2),x[0]==x0};
    loesung=NDSolve[modell,x,{t,0,10}];
    bild=Plot[x[t]/.loesung,{t,0,10},DisplayFunction->Identity]
];
bild=Table[x0=10+10 i; p,{i,5,12}];
abb=Show[Evaluate[bild],DisplayFunction->$DisplayFunction,AxesLabel->{"t","x"},ImageSize->{400,300}];