The first victim of the Anthropophagi that we are introduced to is Eliza Bunton, the unfortunate corpse that Erasmus Gray discovers. Although as a character she's hardly memorable (we only learn her name when Will Henry reads it on her tombstone), she is crucial to setting up the dichotomy of innocent girl versus ravaging monster.
Even though Yancey is careful to remind the readers (through the stern lectures of Dr. Warthrop) that the Anthropophagi aren't evil, they are merely subjects to their instinctual drive to feed, they still need to be horrifying (otherwise they're simply a non-issue). One way to do that is to contrast them with the perfect innocent victim:
My eye was drawn to the stone about which he paced, and the name etched upon it. ELIZA BUNTON. BORN MAY 7, 1872. DIED APRIL 3, 1888. A month shy of her sixteenth birthday when consumed by the indifferent indignity of death's cold embrace, in the first gentle flush of her budding womanhood, only to be pulled into a far less indifferent embrace for a consummation more foul than even the ultimate effrontery of death. In the space of a fortnight, Eliza Bunton had transformed from death's virgin bride to the incubator for a monster's progeny. I turned my gaze from the cold stone to the cold form beneath the white sheet, and my heart ached, for suddenly she was no longer a nameless corpse, an anonymous victim. She had a name—Eliza—and a family who must have loved her, for they had dressed her in the finest raiment and buried her in a necklace of the purest pearls, even arranging her luxurious curls with the utmost care, when all the while her destiny was not to lie in unbroken rest among her brethren, but to be eaten. (3.25)
The pearl, as a gemstone, has become a symbol of purity and innocence in it's own right. So when Dr. Warthrop discovers that Eliza's strand of pearls was the cause of death for the Anthropophagus that was eating her, it is a figurative moment of good defeating evil—or innocence defeating immorality, as Dr. Warthrop would probably prefer we explain it.