Starting with your organic forms with contour lines, these are spot on - simple sausages, confident and accurate, and shifting properly from wide to narrow as we slide along the length of the forms.

Continuing onto your insect constructions, I'm definitely seeing considerable improvement and growth as you move through the set. Some of your earlier drawings (ignoring the demos) - the lobster and ladybug - have a pretty prominent tendency to cut back across the silhouette of forms already present in the construction. This is something you'll definitely want to avoid, as it immediately flattens out your construction by reminding the viewer that what they're looking at is just a series of lines and shapes on a page, rather than a 3D object.

The key there is that once a form has been drawn on the page, you shouldn't attempt to alter its silhouette. This can occur when cutting back across it as shown here, but also when extending it through the addition of new flat shapes, or by simply attempting to redraw its silhouette entirely. Instead, we need to respect the 3D nature of the forms we've drawn, treating them as solid entities, and add further complexity/detail by introducing new, complete, fully enclosed 3D forms to the construction, and defining how they relate to the existing structure to which they're being attached. This is done either by defining the intersection between them (using a contour line, like in the form intersections exercise) or by drawing the silhouette of our new form such that it wraps around the existing structure as shown here.

This can be seen in action in this beetle horn demo and in this ant head demo.

Now, all that said, you definitely improved vastly in this area when constructing your hercules beetle, your bumble bee, and your praying mantis at the end. These constructions show much more respect for the solidity of all the elements that make up your constructions.

One thing that will help you continue developing in this way, is actually something we can most easily explore by talking about how additional masses/bulk is added to your leg structures. You're doing a good job of focusing on the use of the sausage method, and I can see that you're experimenting with different ways to then build upon it to capture further complexity to those areas. In most of these cases, you try to wrap a new form around the sausage, fully enveloping it.

Instead of wrapping it completely (which usually leaves the sausage to either float loosely inside of it, or with some minor areas where the direct relationship between those forms are defined on the ends), break that larger encompassing form into separate masses as shown here. This allows us to define a much more significant contact between the additional mass and the sausage underneath - the silhouette itself makes contact, and so that contact can be defined in 3D space. This can also be applied outside of the sausage method, as shown here. Defining that contact is key. You can also see it being used in this ant leg demo as well as this dog leg demo (since this will be used extensively in the next lesson).

I am very pleased with the improvement in those last three drawings. As such, I'm going to go ahead and mark this lesson as complete. Keep up the good work.