Jumping right in with your organic intersections, these are looking quite good. You're selling a strong impression of how they slump and sag over one another under the weight of gravity, and you're making good progress with your cast shadows as well, wrapping them around the surfaces upon which they're projected and generally minding a single consistent light source.

Continuing onto your animal constructions, I think that there are a lot of strong signs of progress and understanding, but there are a number of points I'd like to call out - some major, some minor, and some of which were raised in my critique of your Lesson 4 work and haven't quite stuck just yet.

The first point I wanted to call out is a fairly minor one relating to your birds' wings. Right now you appear to be drawing them largely as flat shapes (similar to leaves), then drawing feathers roughly within that shape. When it comes to wings, I find it more effective to construct the initial structure as being somewhat more voluminous and solid, and then "attaching" feathers to its surface as shown here. Avoid little pieces of the initial structure sticking out between the feathers, as this will make the wing (which does generally have more volume to it) feel flat and a little unnatural.

Continuing forward, there are a couple central points I want to talk about, and then I'll share a list of smaller concerns. The first central issue has to do with how you're approaching your additional masses. When it comes to additional masses, the way in which their silhouettes are actually designed and shaped matters a lot. One thing that helps with this 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.

As shown here, there are certainly cases where some of your additional masses get very complex (for example the one on the top where one mass was trying to accomplish a lot, and there was very little specificity to how this mass was meant to relate to the existing structure in 3D space). In such a case, breaking it into separate pieces would be far more effective.

Along the lower one, you did break it into smaller pieces, which is good. At this point we can look at how we can specifically place inward curves corresponding with existing structures (whether it's just to wrap around the torso itself, or to press up against the hip or shoulder masses - anywhere you can find some existing structure to press up against helps the new mass feel more grounded, more as though it's part of a 3D puzzle rather than just sitting on its own).

Continuing onto the next topic I wanted to discuss, 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.

I can see individual elements of this approach in some of your head constructions, but generally there are still pieces missing here and there, which suggest to me that you may not be as familiar with this informal page demonstration. I strongly encourage you to apply this head construction approach as directly as you can to your animal constructions. It may not always seem obvious that it can be applied (as there are many differences between different species of animals), but try to apply it as strictly as you can. As shown here on this particularly banana-headed rhinoceros, using this approach as a base and building upon it is generally enough to fit most situations.

Now, the last thing I want to do is quickly go over the other issues I've marked out on this page:

• On the lower stag's head, I noticed that you cut into the cranial ball form's silhouette to refine the head shape. This is something that, as discussed back in Lesson 4 (where we discussed the importance of not altering the silhouettes of forms that have already been drawn, as these are actions taken in 2D space rather than 3D space), should be avoided.

• As an extension of the previous point, there are also areas where you add flat shapes to your construction to 'bridge' between different forms. This may add to the flat drawing on the page, but the information you're adding does not actually have any clear relationship with the existing 3D structure, and thus it cannot be interpreted as something three dimensional.

• When constructing your animals' legs, you seem to regularly use stretched ellipses rather than sticking to the specific characteristics of simple sausages. I strongly urge you to familiarize yourself with the specific points on the sausage method diagram and apply them all consistently. I also provided some diagrams that show how you can build upon those structures to add bulk where it's necessary in my critique of your Lesson 4 work, so I suggest you review those as well.

• Be sure to draw every form with a complete, enclosed silhouette, avoiding having them suddenly get cut off where they're overlapped by another.

• When drawing feet - whether they're paws or hooves - it helps a lot to be mindful of where we place our corners in those silhouettes. Corners in a silhouette can be used to imply the presence of different, separate faces - like a front and side face of a hoof. You can also see this use of "boxy" silhouettes applied more broadly in this other student's work where I demonstrated how a bear paw can be constructed first with a single boxy form, then with individual boxy toes attached to it.

The last point I wanted to talk about from that page is a little more involved - I'm noticing a lot of very heavy use of line weight throughout your drawings, and it can get quite thick along the silhouettes of your forms. Keep in mind that as with all the tools we're using here, those tools are best put to work towards specific goals, and when it comes to construction, when we allow ourselves to use line weight in a more general sense, we can end up using it as a swiss army knife to solve problems it's not really meant to address.

For example, some students try to use line weight to hide mistakes - for example, they might be slightly off with a mark, draw another in its place, and then fill in the gap between them. Unfortunately, this is not a harmless decision - it results in a much thicker area of linework, which they draws attention where it shouldn't. In other cases, one might try to use line weight to reinforce the silhouette of their entire object - but when we allow our line weight to jump across from one form to another, we risk creating those little "bridging" flat shapes, introducing 2D elements to what should be a purely three dimensional construction.

Then there's the simple matter that when we try to apply line weight to an extensive section of a silhouette, we end up tracing over it more hesitantly, rather than employing the ghosting method as we should be for each mark we make.

Fortunately, there is a specific way in which line weight can be used that will both help to clarify our drawings, and avoid these pitfalls. It is to focus the use of line weight on establishing how different forms in our constructions overlap one another, by limiting its use only to the localized areas where those overlaps occur. You can see this in action in these two overlapping leaves, where the fairly limited application of line weight helps establish which one's in front, but without going back over the whole thing. This also allows us to execute those marks with more confidence, maintaining a smoother stroke, while keeping the line weight subtle, like a whisper to the viewer's subconscious and avoiding its overuse.

Now, I've laid out quite a few things for you to consider here. I'm going to leave you to that, and when you feel you've gone through my feedback enough to absorb it well, you can get to work on the revisions I've assigned below.