Who is Newt from Welcome to the Monkey House and what is their importance?

Newt is a twenty-year-old private in the Artillery. When he hears from his mother that his childhood friend Catharine is getting married, he goes A.W.O.L. from the Army to come see Catharine and tell her he loves her. The narrator describes him as "shy," and his speaking habit as "absent," "even in matters that concerned him desperately."