As Hyde represents the evil side of Jekyll, this size difference suggests that the author views this side of the human character to be in some way lesser than the good and rational side.

Humans differ from all other creatures because of their rational structure - their capacity ... passage does not mean that God is in human form, but rather, that humans are in the image of God ...

What do a human, a rose, and a bacterium have ... to argue that DNA actually takes the form of a double helix, a ladder-like structure that is twisted along its entire length (Figure 6).