What's with the cherubs?by Juan Carlos Martinez
Here are a few things on Cherubs and Putti for you, Richard.
Originally, Cherubs and Putti had distinctly different roles, with the former being sacred, and the latter, profane. That is, Cherubs and Seraphs (Cherubim, Seraphim) are Angels, occupying the highest angelic orders in Heaven and are thus the closest to God. On the other hand, Putti, arise from Greco-Roman classical mythos (i.e., non-Christian). They are associated with Eros/Cupid as well as with the Muse, Erato; the muse of lyric and love poetry.
Cherubs (and Seraphs) were often depicted simply (and creepily) as winged heads This was done to show that they are incorporeal -- literally; without a body -- yet intelligent and thus, Divine. In paintings, they usually accompanied any of the Holy Trinity, as well as, later, the Madonna.
Putti -- which comes from the Latin, putus, meaning "little man" -- are, as Tim pointed out, not so much babies as they are 'not human'. They are spiritual beings and thus depicted in their typically odd fashion; as winged little people of indeterminate gender. Using babies as models for Putti (or for Cherubs, either) doesn't quite get across the true concept of "Putti-ness" as they (babies) are too guileless, for one thing, whereas Putti are clever and purposeful. They are there to help Cupid/Eros
facilitate the onset of profane love -- or secular, non-religious love, as between two people, rather than the love as between a human and God. Probably, it was artists' attempts to avoid simply painting babies that has led to so many rather odd and, often, ugly, Putti. Sometimes they nailed it, sometimes not.
By the time the Baroque Era came about, which might arguably have been the high point for Cherubim and Putti, both of these little beings were usually being depicted in the same way. Which one they were, simply depended upon the theme of the painting or sculpture: If religious (sacred) -- they were Cherubs. If secular or mythic (profane) -- they were Putti.
In either case, they'd be hard to pull off successfully today because most people are unaware of their roles in semiotics, or in philosophy/mythology/history, or in religion.
Hope it helps.