TMB-
The halacha differentiates between ‘Kinyan Issur’ and ‘Kinyan haGuf’. Kinyan issur means that you go through a procedure in which you make an act of acquisition but you don’t actually acquire anything, you just have new rules that apply to you. Kinyan haguf is when you actually acquire the item. A slave is a kinyan haguf. A woman is only a kinyan issur; a man doesn’t own his wife. This is in the gemara. It’s probably what the Wolf was referring to.