Bone marrow donation between siblings is a common medical procedure. In some instances, the donor will be a young child incapable of providing either consent or assent, and the intervention is made lawful through the consent of the parent(s). Although a number of justifications have been formulated to cover this act with legitimacy, these fail to describe accurately the transaction that takes place. In the absence of the child authorising his parents to act as his proxy, it is unclear why parental consent is sufficient to permit the redistribution of his biological wealth. Instead, where the donor is such a young child, the whole procedure may be construed as the appropriation of bodily tissue from one unconsenting human and its conveyance to a third, albeit related, party. This paper argues that if the parentally authorised transfer of biological material from an unconsenting human to another is legally permissible, it must be on the basis of an implicitly acknowledged property right in the child.