But no one probably will dispute that the butterfly is higher than the caterpillar.

In some cases, however, the mature animal must be considered as lower in the scale than the larva, as with certain parasitic crustaceans.

To refer once again to cirripedes: the larvae in the first stage have three pairs of locomotive organs, a simple single eye, and a probosciformed mouth, with which they feed largely, for they increase much in size.