Starting with your organic intersections, these are generally coming along well, with one small caveat - on the first page especially, and to a lesser extent on the second, you're drawing these sausage forms as though they're kind of... melty. That is, there's a lot more complexity in some of their silhouttes (like this one for instance) where they're conforming to the structures beneath them a little too much. Instead of thinking of them like melted cheese, try and treat each sausage more like a water balloon that is very full. It'll bend along its entire length, but it won't seep into cracks and crevasses so readily.

Continuing onto your animal constructions, it's very clear to me that you've put a lot of effort into addressing the point I raised in Lesson 4's critique about ensuring that every addition is its own complete, self-enclosed structure, and that we build them up gradually, designing their silhouettes such that they wrap around the existing structure. I think that for the most part, you've done a good job with this - although as shown here and here I did catch a few tiny spots where you appeared to cut into your silhouettes a little (in red) and where you extended them (in blue). That said, your intent is clear, and that is what I care about.

That said, there can be some improvement here, specifically in the way that the additional masses' silhouettes are actually being designed. One thing that helps with the shape here is to think about how the mass would behave when existing first in the void of empty space, on its own. It all comes down to the silhouette of the mass - here, with nothing else to touch it, our mass would exist like a soft ball of meat or clay, made up only of outward curves. A simple circle for a silhouette.

Then, as it presses against an existing structure, the silhouette starts to get more complex. It forms inward curves wherever it makes contact, responding directly to the forms that are present. The silhouette is never random, of course - always changing in response to clear, defined structure. You can see this demonstrated in this diagram.

In this regard, a lot of your additional masses have some elements of purposeful design to them, but they also still have a tendency to be quite blobby, without the clear, specific corners they need to create a much more believable relationship with the existing structure. You're not far off though. Here's how I'd have approached some of the masses on number 4.

Similarly, avoid making additional masses too big, and trying to get them to do too much. For example, here we can break that mass along the back into separate pieces, with each one's silhouette (and all of their inward curves) serving a more specific purpose.

As we progress, I do think that your additional masses become more intentional, with those here definitely being a step up from the earlier ones. Still a bit blobby when it comes to where we need more specific, sharp corners, but definitely improving. That said, when we get to this one, a lot of those little masses along this ibex's spine, like here. Not only do you end up with masses whose silhouettes are very complex right off the bat, there's also a lot of inward curves that serve no purpose.

Breaking them up further as shown here is the way to go - and you can actually combine different forms to build up to what ultimately are inward curves, while still adhering to that idea that unless something is actively pressing up against your mass, you always go for the simpler outward curve. That said, don't worry too much about really small specifics - remember that the drawings we do in this course are exercises. It's all about solving the puzzle that is building up in the direction of our reference image, not about replicating that reference image at all costs. In solving the puzzle, we develop our brain's understanding of what we've drawn and how it exists in 3D space.

That about covers the bulk of my concern with your drawings, but I do want to take a quick moment to talk a bit about our lord and saviour, head construction. Lesson 5 has a lot of different strategies for constructing heads, between the various demos. Given how the course has developed, and how I'm finding new, more effective ways for students to tackle certain problems. So not all the approaches shown are equal, but they do have their uses. As it stands, as explained at the top of the tiger demo page (here), the current approach that is the most generally useful, as well as the most meaningful in terms of these drawings all being exercises in spatial reasoning, is what you'll find here on the informal demos page.

There are a few key points to this approach:

• The specific shape of the eyesockets - the specific pentagonal shape allows for a nice wedge in which the muzzle can fit in between the sockets, as well as a flat edge across which we can lay the forehead area.

• This approach focuses heavily on everything fitting together - no arbitrary gaps or floating elements. This allows us to ensure all of the different pieces feel grounded against one another, like a three dimensional puzzle.

• We have to be mindful of how the marks we make are cuts along the curving surface of the cranial ball - working in individual strokes like this (rather than, say, drawing the eyesocket with an ellipse) helps a lot in reinforcing this idea of engaging with a 3D structure.

Try your best to employ this method when doing constructional drawing exercises using animals in the future, as closely as you can. Sometimes it seems like it's not a good fit for certain heads, but with a bit of finagling it can still apply pretty well. To demonstrate this for another student, I found the most banana-headed rhinoceros I could, and threw together this demo.

So! As a whole I'm pleased enough with the direction of your progress that I think you should be good to continue working in these things on your own. I'll go ahead and mark this lesson as complete.