The Twenty-Second Conference on Avian Medicine and Surgery included a lecture on Gram's Stain Interpretation by Heidi Hoefer, DABVP (Avian). The text for this lecture is included in the Proceedings for the 2001 Conference. The slides used in the lecture are available here. Double click on image for larger view. 
These slides are copyrighted and remain the property of Dr. Heidi Hoefer

Gram Positive             Gram Negative              Clostridia    

Giardia                         Giardia                 Mycobacteria

Pseudohyphae              Red Blood Cells              Spirochetes   

Urate Crystals                 Yeast