AUTHOR S ABSTRACT OF THIS PAPER ISSUED 

 BY THE BIBLIOGRAPHIC SERVICE, JULY 19 



EFFECTS OF CHEMICALS ON REVERSION IN ORIENTA- 

 TION TO LIGHT IN THE COLONIAL FORM, SPON- 

 DYLOMORUM QUATERNARIUM 



S. O. MAST 

 Zoological Laboratory of the Johns Hopkins University 



CONTENTS 



Introduction 503 



Material and methods 506 



Effects of chemicals — General statement 507 



Effect of acids 508 



Effect of alkalis 512 



Effect of chemical concentration 514 



Effect of time-rate of change in chemical concentration 515 



Effect of physiological states 516 



Effect of anesthetics 516 



Effect of temperature and illumination ■. 517 



Discussion 518 



Summary 519 



Literature cited 520 



INTRODUCTION 



The problems in behavior may be divided into two groups, one 

 containing those which concern the nature and the cause of 

 responses, the other those which concern the cause of changes in 

 responses. The problems in the former group deal extensively 

 with the relations between the responses and the environment or 

 certain processes within the organism; those in the latter deal 

 primarily with habit formation or learning, regulation or adapta- 

 tion and evolution, i.e., with some of the most fundamental char- 

 acteristics of living matter. 



The investigations which have thus far been made in behavior 

 belong largely to the former group. Many observations have, 

 however, also been made on changes in the responses. In fact, 

 from a qualitative point of view, the whole field has been surveyed 



503 



THE JOURNAL OF EXPERIMENTAL ZOOLOGY, VOL. 26, NO. 3 



