Celli

Now, against the Beethoven rhythm and the antiphonal outcry (E), the 'celli intone a spacious and somber melody whose beginning is shown at F.

Source: wiktionary

The dynamics of the celli have to be extended to the basses, for it would not make sense to have the basses operating under their last dynamics mark, of the previous bar, which is ppp.

Source: wiktionary

The balance of strings in these two orchestras emphasized the lowest tessitura; Charles Burney criticized the Italians for having more double basses than celli and for playing the instrument "... so coarsely that it produced a sound no more musical than the stroke of a hammer."

Source: wiktionary