CONTRIBUTIONS FROM THE ZOOLOGICAL LABORATORY OF THE MUSEUM OF 

 COMPARATIVE ZOOLOGY AT HARVARD COLLEGE, E. L. MARK, Director, No. 210 



A COMPARISON OF THE REACTIONS OF A SPECIES 

 OF SURFACE ISOPOD WITH THOSE OF A SUBTER- 

 RANEAN SPECIES 



PART II 

 A. M. BANTA 



I. Experiments with mechanical stimulation 440 



1 . With bristles 440 



2. With localized currents of water 447 



3. With the concussion produced by a falling solid body striking upon a surface of wood 453 



4. With vibrations, 100 per second 46 1 



5. General summary of experiments with mechanical stimulation 463 



II. Experiments with the animals in currents of water 467 



1 . Asellus 469 



2. Csecidotea 470 



in. Study of the food 477 



rV . General discussion 479 



V. Summary 485 



VI. Bibliography 4S8 



This paper is the second of a comparative study of the reactions 

 of the surface isopod Asellus communis Say and its widely dis- 

 tributed subterranean relative Caecidotea stygia Packard. The 

 studv was undertaken to determine in what ways and to what 

 extent these animals differed physiologically and to learn why the 

 one animal is a cave inhabitant while the other, its near relative 

 living in the same region, rarely occurs in caves. 



' Part I, on the reactions to light, has already been pubUshed in the Journal of Experi.mental 

 Zoology, vol. 8, no. 3, p. 243. 



THE JOURNAL OF EXPERIMENTAL ZOOLOGY, VOL. 8, NO. 4. 



