How have courts dealt with the issue of an adopted child's claim for equal share of a deceased's property?

In Lamb's Estate v. Morrow (1908) 140 Iowa 89, 117 N.W. 1118, 18 L.R.A., N.S., 226, the recipient of property from the decedent claimed that he was entitled to the more favorable tax treatment accorded to an adopted child. He argued that although he had not been legally adopted, he had been equitably adopted, and that in fixing the tax the equitable aspects of the case should be considered. The court stated, beginning at page 1120 of 117 N.W: 'The answer to this is that the case is not in equity, and if it were, the matters relied on cannot make one an heir if in fact they do not in law establish that relation. * * * Holmes does not, in any event, take as an heir'. The same answer is equally applicable to the contentions of the child here.