fc>r, f 



-> 1 ' 



MOVKM?]NTS, ETC, OF riJESFI-WATER rr,AN A 1(1 ANS. 509 



';i>tx 



The Movements and Reactions of Freshwater 

 Planarians : a Study in Animal Behaviour.' , 



By 



Kayiiioiid PcnrI, Pli.D. 



(rnsfniRlnr in Zonlotry in tiic Univcisily of Mirliipjan, Ann Arbor, 

 Michigan, U.S.A.) 



Contents. 



A. Tntkodtjction . 



B. l^ESUME OF LlTERATUKE . 



I. Morplioiogical and Systematic 

 JI. Pliy si logical 

 c. Material 



D. Habits and Naturae History 



I. Occurrence and Distribution 

 II. Activities 



a. Sensitivity 



h. Secretion of Mncus 



c. Periods of Activity and Rest 



d. Formation of Collections . 



e. Movement on Surface Film 



III. Food 



IV. Defecation 



V. Summary of Factors in JJcliaviour 



E. Normal Motor Activities 



I. Locomotor Movements 

 a. Gliding 



1. Rate of Gliding Movement 



2. Direction . 



52G 

 527 

 527 

 529 

 532 

 533 

 534. 

 535 

 537 

 538 

 539 

 539 

 539 

 545 

 548 



' Contributions from the Zoological Laboratory, University of Michigan, 

 Ann Arbor, Michigan, No. 58. 



VOL. 46, I'ART 4. NKW SERIES. LL 



