CONTENTS. 
Transactions : 
Page. 
‘ 1 What is Matter” (Annual Address by the President) 
Dr. Sidney E. Mezes 5-18 
“Studies on Avian Anatomy,”' 
Margaret E. Marshall, M. A 19-41 
“The Beginnings of the Texas Railroad System,” 
Alexander Denssen, M. S 42-74 
“On Reproduction, Animal Life Cycles and the 
Biological Unit,” 
Dr. Thomas H. Montgomery, Jr 75-94 
Proceedings : 
Officers for 1906-1907. 96 
Titles of Papers Read Before the Academy During 1906 97-98 
List of Patrons and Fellows 99-100 
List of Members 101-102 
