Careful there, Spade. You're giving this guy an excuse to geek out.

Aximili's thought-voice warms as he turns to one of his favorite subjects. «That is an interesting question. In fact, the first prototypes for the morphing technology only allowed one to morph into organisms smaller than oneself, because no one could yet determine a source of mass for larger morphs. Later, when a scientific exploratory craft took readings in Zero-space, it was determined that mass funneled into Zero-space is not necessarily individualized, which to say that one organic molecule is as good as any other. Upon demorphing, the mass restored from Zero-space may not be the same mass directed there in the first place. A good way to envision this is a "bank" of mass floating in Zero-space, from which anyone may make a withdrawal or a deposit. When I morph a cockroach, I make a deposit to this bank of mass. When I morph an elephant, I make a withdrawal. Of course, none of the aforementioned applies to the brain. The brain must remain individualized in Zero-space in order to maintain a connection between one's original mind and that of the creature one has morphed.»

Kudos to Spade if he understood that.