According to Vārttika 5 on Pāṇini, 4.2.36—aver dugdhe soḍhadūsamarīsacaḥ—the ‘suffixes’ soḍha-, dūsa-, and marīsa- are added to the stem avi- ‘sheep’ in the sense of ‘milk’. These elements cannot be suffixes in the ordinary sense of the term, but rather words appearing as the second members of the respective compounds. The reason that they were treated as suffixes by the grammarian was no doubt the fact that the words were not used independently, but only as members of these compounds. Originally, however, they must have existed as independent words.