Elselijn Kingma argues that, in cases of mammalian placental pregnancy, the foster (roughly: the post-implantation embryo/fetus) is part of the gravida (the pregnant organism). But she does not consider the possibility of proper overlap. I show that this generates a number of serious problems for her argument, and trace it to a quite general issue within the literature on biological individuality. Doing so provides an opportunity to pull apart and clarify the relations between some importantly distinct questions concerning organismality and organismic parthood, and to identify the implications that this has for those who want to draw on this literature when making metaphysical or mereological arguments.
- Biological Individuality