What was his reason for telling Mary Anne that Julius died and never mentioning Vincent? And why did he tell Julius she died and ship Vincent off to an orphanage? I always took it that he was just a slimeball, but what was the reason behind him doing it?
If I were going to dig and come up with a legitimate reason I would say because due to the birth of Vincent the experiment 'failed'. So therefore Traver salvaged what he could out of situation. He told Mary Ann they died so she wouldn't try to split her attention between the two. Then he isolated Julian by lying to him, giving him a chance to flourish the way he had originally envisioned. He sent Vincent to an orphanage because he honestly didn't care about him. Vincent would have been lied to as well so he wouldn't go looking.
He really was a dick to Vincent. If he was so interested in naming this young baby and all the while thinking he was going to wind up a loser, why even do it in the first place??!! He really was a Douche Wagon!!!!