You missed it, or maybe your translation left it out? Search for 'Apothetae':
> Nor was it in the power of the father to dispose of the child as he thought fit; he was obliged to carry it before certain triers at a place called Lesche; these were some of the elders of the tribe to which the child belonged; their business it was carefully to view the infant, and, if they found it stout and well made, they gave order for its rearing, and allotted to it one of the nine thousand shares of land above mentioned for its maintenance, but, if they found it puny and ill-shaped, ordered it to be taken to what was called the Apothetae, a sort of chasm under Taygetus; as thinking it neither for the good of the child itself, nor for the public interest, that it should be brought up, if it did not, from the very outset, appear made to be healthy and vigorous.
Thanks. I just remembered the emphasis of Children belonging/being raised by the community. Still don't necessarily think it's right to interpret those few sentences as evidence there was rampant child sacrifice like Carthage.
> Nor was it in the power of the father to dispose of the child as he thought fit; he was obliged to carry it before certain triers at a place called Lesche; these were some of the elders of the tribe to which the child belonged; their business it was carefully to view the infant, and, if they found it stout and well made, they gave order for its rearing, and allotted to it one of the nine thousand shares of land above mentioned for its maintenance, but, if they found it puny and ill-shaped, ordered it to be taken to what was called the Apothetae, a sort of chasm under Taygetus; as thinking it neither for the good of the child itself, nor for the public interest, that it should be brought up, if it did not, from the very outset, appear made to be healthy and vigorous.
http://classics.mit.edu/Plutarch/lycurgus.html