Ryzel planned to keep researching about the things related to the sea creatures that they saw, and it might take him a few days to have some basic understanding of it.
And to research more things about it, he would probably have to devote more time to it than just a few days.
So, most of the time he also had to use the samples that they got. He couldn't just let Layton accompany him every time he would use those samples, as it would just waste Layton's time.
Layton also had to be busy with some things, so he couldn't just delay him because of what he was doing, as it isn't cost-effective at all.
He had also told Layton before when he was researching some poisonous plants, but Layton still stayed to watch over him whenever he was researching some poisonous plants.
But at that time Layton wasn't busy and was even helping in some of his research, as he didn't have anything to do, so Ryzel just let Layton watch over him without saying anything.
