> there must have been reference to the grinning of C. Cat even before his time

Indeed there was .. see the end of the linked thead
I thought it was summed up quite well in the thread, kummini.
We now know that Mr. Carroll's use of the infamous cat could be due to anything from some Irish cheese's shape, to a childhood memory; perhaps a carefully crafted and profound meta isis, or a mixture of all of the above...
His cat character has certainly long mystified readers, I guess ideally leaving them as perplexed as the sweet little protagonist. Be harmoniously confused, I know I am.