The mixed English-Latin text makes fun of the difficulties of Latin declensions. It takes off from puns on the English words "motor" and "bus", ascribing them to different declensions in Latin, and conjugating them.
At the time of writing Godley, a distinguished Classical scholar, was resident at Oxford University. The poem traditionally commemorates the introduction of a motorised omnibus service in the city of Oxford (Corn and High are the colloquial names of streets in the centre of the city where several Colleges of the University are located), thereby shattering the bucolic charm of the horse-drawn age. It has since also been cited in the context of the recent introduction of larger vehicles (including "bendy" buses).
The poem owes its continuing popularity to the large number of pupils who had to learn Latin as a compulsory subject for University entrance (not just Oxford and Cambridge) in the United Kingdom. Most of them will have used a "primer" in which Latin nouns were "declined" (the correct declensions written out), for example, servus, serve, servum, servi, servo, servo (depending upon the order in which the cases - nominative, accusative, dative, etc. - were cited). The poem provides leavening to what is a very dry subject for most school pupils.
The poem is quoted by Dorothy L. Sayers in her well-known essay "The greatest single defect of my own Latin education".