1. blf says

    The mildly deranged penguin points out that deciding which students go into which vats is a complicated business. There are simple physical considerations, such as the size of vat, of the student, of the professor, which is stronger, and who has the chainsaw. Then there are biochemical considerations, such as is the stuff in the vat capable of dissolving / mutating this student, the pH & other levels, not-confounding long-running experiments, and whether or not the student would be toxic to the creatures already in the vat.

    Other considerations include what the ethics panel allows, and this is where all of the mad professor’s current paperwork comes in. One thing he has to do is show the students are indeed sentient, which can be remarkably difficult. There’s also the challenge of distinguishing between actual students and disguised jabberwocks and snarks.