The document summarizes the external coverings of various microorganisms, plants, invertebrates, and vertebrates. It describes that microorganisms like viruses have protective protein capsids, plants have waxy cuticles covering their epidermis, invertebrates like arthropods have an exoskeleton made of chitin, and vertebrates range from fish with scales to mammals with hair, nails, and glands in their skin. The external coverings provide protection and vary across the different kingdoms.

1. Survey of External Coatings of Microorganisms, Plants, Invertebrates and Vertebrates