Follow up on our discussion of the (non-)existence of the past tense stem morphome in Lithuanian.  The possibility arose that the vowel-changed stem might be a sort of participle, on the intuition that, historically (in Indo-European at least), past tense might arise from a perfect participle.  From there, it was just a short step to asking about the connection between the Latin t-stem, a perfect participle in its most prominent use, and the Lithuanian putative past stem.  I remarked that, as in Lithuanian, I thought the Latin t-stem was used for a repetitive verb formation.  For someone who can't remember any of your names on demand, my memory for facts and analyses form the linguistic literature has proven remarkable.  Here's a table from Aronoff of the uses of the Latin t-stem:

I also think the connection between the theme vowels in Latin, as in Erik's analysis, and the Lithuanian augments is intriguing.