Botanical Drawing II - Fourth Class

In class four we focused on seeing color values in gray scale.  It is kind of tricky to look at an object like a pear and then translate the colors you see on a 9 point gray scale.  For homework we had two exercises.  Here the object is to render the values of the pears very quickly and crudely, but clearly blocking out the various values.  I am not at all sure i got this right.  

The other exercise was to draw a leaf we were given in class.  It is a several step process.  First we had a photocopy of the leaf and traced the outline and major veins.  Then we copied that twice more onto tracing paper.  On the second tracing we blocked out the areas where the light rakes across the leaf.  In the third tracing we added values to indicate color.  The first tracing we transferred to good drawing paper.  Then we toned the whole leaf, referencing the two tracings so we never lost sight of the major light forms.  This is tracing two and three:

This is the leaf on paper: