But it may be objected that if all organic beings thus tend to rise in the scale, how is it that throughout the world a multitude of the lowest forms still exist; and how is it that in each great class some forms are far more highly developed than others?
Baina honako hau kontrajar daiteke, alegia, izaki organiko guztiek eskalan gora egiteko joera badute, nola gertatzen den munduan zehar oraindik ere makina bat beherengo forma existitzea; eta nola gertatzen den klase handi bakoitzean forma batzuk beste batzuk baino askoz ere garatuagoak izatea.