  A problem for any account of the original mixture is Anaxagoras’ mention of seeds. The word for seeds (spermata) occurs twice in the fragments, in lists of ingredients (in B4a and in B4b), but Anaxagoras nowhere explains or makes it clear what it means. There are a number of options: seeds have been taken to be the smallest possible bits of ingredients (but, as argued above, there are no smallest bits in Anaxagoras’ system), or to be extremely small homunculi-like ingredients that some interpretations take to be origins for Anaxagoras of living things which then expand by the addition of other ingredients (Lewis 2000). Furley 1976 and 2002 advocates the simplest interpretation, that Anaxagoras simply means biological seeds (but not homunculi), and this seems the best proposal (see also Barnes 1982, Curd 2007, Sedley 2007, Marmodoro 2015, 2017, 147–153; Marmodoro also sees seeds as biological, containing pre-existing structures). A seed would then be a biological origin point, and might perhaps be the route through which nous (which controls all things that have soul, i.e., anything alive) enters a living thing. If a seed is mixed with the right ingredients in the right circumstances, a living thing will grow.