THE 



KANSAS UNIVERSITY 

 SCIENCE BULLETIN. 



Vol. V, No. 9— April, 1910. 



(Whole Series, Vol. XV, No. 9.) 



CONTENTS: 



The Hackberry Psylla, Pachypsylla celtidis-mamm.e Riley. 



A Study in Comparative Insect Morphology, . . H. B. Stough. 



PUBLISHED BY THE UNIVERSITY 

 LAWRENCE, KAN. 



Entered at the post-offce in Lawrence as second-class matter. 



