> comic verse consisting of five anapestic lines

Hm, yes, it can be – but the form is not exactly set in concrete.

Personally, the structure I think most satisfying is:
Rhyme scheme: AABBA
Lines 1,2,5: 9 syllables in 3 amphibrachic feet
Lines 3,4: 6 syllables in 2 anapestic feet

The unity of triploid feet helps weld the thing together, but the variation in stress patterns makes for more interest. This gives the characteristic declamatory inversion of normal speech rhythm in the first line ~ “There WAS an/old MAN of/deVIZes….” The alteration to anapaest in the middle couplet has something of the same kind of effect that a couplet does in a 14 line sonnet, but sprung into the humorous conclusion of the final line with both rhythmic stress and final rhyme striking conclusively as a closing bell (apart from variation for more humorous effect!)


and now we return you to your regular program...