Starting with your organic forms with contour curves, overall you're doing quite well, but there are just a couple things to help you keep getting the most out of these exercises:

• Draw longer sausages - making them shorter tends to result in more bean-like shapes, which can make it more difficult to focus on the characteristics of simple sausages.

• Don't neglect to include the central minor axis line, as you did on the second page.

• Be sure to draw through your ellipses two full times before lifting your pen. You obviously mean to do this, but you tend to stop around the 1.5 mark.

• Sometimes you demonstrate this, sometimes you don't - remember that as we slide further away along the length of a sausage form, the degree of your contour curves should get wider, as explained in the Lesson 1 ellipses video.

• This is an issue I only saw once, but I wanted to call it out anyway. As seen here, you have an ellipse on the left side, telling us that the left side is facing the viewer. But the next contour line that follows is oriented in such a way that contradicts it. That contour line suggests the left side is pointing away from the viewer. Both contour curves in fact suggest that the far right side is pointing towards the viewer, although there's no ellipse on that side. Technically none of this has to be wrong - the left side could end up turning towards the viewer somewhere in between the ellipse and contour curve, and technically you don't have to place a contour ellipse on the right side for it to face the viewer. But, based on what I'm seeing, it doesn't look like those were things you chose not to do - rather, it seems you might have just been a bit careless here, so keep an eye on that.

Continuing onto your insect constructions, it seems you've gotten ahead of me, and have definitely seen some of the stuff I provide for feedback at this stage. Nothing wrong with that, but it does mean that your work is, as a whole, very well done. One of the main principles I focus my Lesson 4 critiques on is the idea of actions we can take that occur strictly in 2D space (where we're drawing individual lines, or partial shapes, but without providing any information on how those additions relate to the existing, 3D structure), and actions we can take that occur in 3D space - where we're thinking about our new addition as a complete form (with its own fully self-enclosed silhouette), and where everything we draw is executed in such a way that it respects and reinforces the illusion that the existing structure is 3D, rather than contradicting it.

One significant way in which the existing structure can be contradicted by simply cutting across the forms of those silhouettes, as shown here - although it really happens with any actions that alter the silhouettes of those forms, even extending off them. Instead, whenever we want to build upon our construction or change something, we can do so by introducing new 3D forms to the structure - forms with their own fully self-enclosed silhouettes - and by establishing how those forms either connect or relate to what's already present in our 3D scene. We can do this either by defining the intersection between them with contour lines (like in lesson 2's form intersections exercise), or by wrapping the silhouette of the new form around the existing structure as shown here.

As a whole, you've done a great job of holding to this - except for a few spots:

• This ant adds those extensions on the left and right of the head (and do similar things for each of the sections of its body to expand them out). These are modifying the silhouettes of the initial masses, rather than building onto them in 3D space. Here's a demo of an ant's head that is similar, but done by adding actual forms in 3D space. Note how the left and right sections have clearly defined relationships with the existing structure that wraps along the surface of the initial head mass.

• I'm not entirely sure on what's going on here but on this shrimp's thorax you appear to have what looks either two forms superimposed on one another (the sausage and the ball form) or you modified the sausage's silhouette after the fact.

Overall however, you have largely focused on working additively, and have generally shown a lot of great segmentation with new forms wrapping around the existing structures (like on the shrimp's abdomen).

The only other thing I wanted to call out was your use of the sausage method. Generally speaking you've done this really well, although you do appear to frequently forget to define the joint between the sausage segments, which is important when it comes to making those legs feel solid.

I do however have some additional information relating to wrapping masses around the existing sausage structures, which you referenced in your submission comment but didn't really apply in your work except for a couple spots (so I assume that you saw it in conversation on discord but didn't necessarily see the whole explanation I generally provide in my critiques). Ultimately once our sausage armature is in place, we can then build on top of this base structure with more additional forms as shown here, here, in this ant leg, and even here in the context of a dog's leg (because this technique is still to be used throughout the next lesson as well).

Just keep in mind that we're not only focusing on forms that impact the silhouette - we're considering everything like a 3D puzzle, as the internal/in-between forms help establish the way in which the rest of it all fits together.

Anyway, all in all, great work. I'll go ahead and mark this lesson as complete.