Abstract: This invention relates to improvements in the manufacture of devices applicable to dolls that simulate physiological functions. On exerting pressure on a tank of water situated in the interior of the doll, a tube which commences in the interior of the tank below the level of the water, conducts a small flow of the said water towards the interior of the mouth of the doll and surrounding areas, although in a position in the mouth in front of a second tube which commences in the interior of the tank and in the area not occupied by water, with the purpose that the same pressure should originate a current of air which, on emerging adjacent to the first tube and also in the interior of the mouth, causes the creation of small bubbles and the outlet of small amounts of water that simulate the dribbling of the doll and because a third tube for filling the tank also commences in the interior of the mouth of the doll so that on placing a bottle of water into the mouth the filling of the tank is produced.