IV CONTENTS 



No. 3 



1. A Theorem on Differential Functions 127 



S. Epsteen, Ph.D., 



Assistant Professor of Engineering Mathematics 



2. On an Algebra in Three Units 129 



S. Epsteen, Ph.D., 



Assistant Professor of Engineering Mathematics 

 and 

 Harry V. Welch, B.A. 



3. The Appeal of Alexius for Aid in 1095 135 



Edward Tuthill, M.A., 



Assistant in History 



4. Scientific Expedition to Northeastern Colorado . 145 



Members of Museum and Biological Staffs 



5. The Mollusca of Colorado, Part II 167 



Junius Henderson, 



Curator of the Museum 



6. The Silva of Colorado. II. The Poplars, Aspens and 



COTTONWOODS 187 



Francis Ramaley, Ph.D., 



Professor of Biology 



No. 4 



I. The Increase of Divorce 203 



John B. Phillips, Ph.D., 



Professor of Economics and Sociology 



3. The English Church and the Lay Taxes of the Four- 

 teenth Century 217 



James F. Willard, Ph.D., 



Assistant Professor of History 



3. Shakespeare and Psychognosis. Essay IV . . . . 227 



Melanchthon F. Libby, Ph.D., 



Professor of Philosophy 



4. The Bees of Boulder County, Colorado .... 239 



T. D. A. Cockerell, 



Professor of Systematc Zoology 



5. The Protozoa of the University Campus . . . 261 



