The man had measured the length of their arms; checked with calipers the thickness of the skin below their eyebrows; had them execute the standing broad jump and a complex version of hopscotch.

Even the physical fitness segment of our program he did well in, better than most other boys save for the broad jump.

Then the author makes a deductive broad jump to the idea that radiation produces creatures "as far beyond us as we are beyond the ape-man."