[MUSIC] So here what we've said is that the telencephalon expands to cover over the rest of the brain. And, in fact, what we also said is that the telenchephalon is joined to the rest of the brain only by a couple of places. And I want to show you that. I, I showed you that this is the top of the diencephalon here and it's separate. But, what I've done in this dissection is I took it out. So, now what we're looking at is. I've taken out the telencephalon. I've taken off the telencephalon. We'll look at that in a moment. I've also taken off the cerebellum. So, what we're look at is the back side This side, the back side, of the medulla, the pons, and the midbrain. And now here, this is the diencephalon, this is the thalamus. If we look around on this, on this side now we see it looks a little bit more familiar. Here is the medulla. Here is the pons. We can see a little bit of midbrain. The midbrain's pretty small. And then here is the base of the diencephalon, which is the which is the hypothalamus. So let's look at what we removed. What we removed is the telencephalic cap. So, here's the front, here is the back. This is the middle, and you can see that most of the brain is this, is the telencephalic cap. And the rest of it, the, the brain stem and the diencephalon just fit nicely into here. And actually most of the rest of it, so this is fitting in, like this. Exactly like that. And then the cerebellum is, is right here. And we can take that out. And what you're looking at down here, this piece right here. That is the corpus colossum. That's that fiber tract, that highway that is, is connecting the two sides of the brain. So now what we're going to do. I, I realize that I made this dissection and you don't. It's not as compelling since I've already done it. We're just going to try and do the same thing on this half of the brain. We're going to try and separate out the brain stem and diencephalon from the overriding telencephalon. And what you'll see is that it's almost all separate. It's joined off on the side and that's what I'm going to cut. [BLANK_AUDIO]. All right, so I've cut that side bit. And now, I'm taking this out and you can see that that's a smooth surface. And now, I have to cut one little place here at the front end. I didn't do a great job, but what you can see is that the only cut I ever had to make was the off here on the side. Here we have the pons, the medulla, the cerebellum, pons, medulla, cerebellum. Here's spinal cord, and the only thing that joined this whole part of the brain to the telencephalon is off here on the side. Let's look at it again. You can see the smooth surface if I done it a little bit better. I would have gotten more of this smooth surface. This is the top of the diencephalon and the telencephalon just sits on top of it. It is not connected. So, we've got this tube and then something coming back on top of it. [MUSIC]