516 RAYMOND PEARL. 



are of importance from the present standpoint. Aiuon 

 such references the following may be noted : 



Moseley ('74), in a paper concerned principally with the 

 anatomy and histology of the land plaiiarians, devotes a sec- 

 tion to a discussion of the habits of these forms. He com- 

 ments on the ''avoidance of light" (negative phototaxis) of 

 hind and aquatic planarians, and discusses the habitat and 

 food of the animals. He reaches the conclusion that all 

 plauariaus are carnivorous, but gives no account of the 

 method of feeding. He quotes Rolleston as having found 

 that Planaria torva and Deudrocoelum lacteura in a 

 dish in which had been placed a freshly killed earthworm 

 " crowded on to the worm's body and soon sucked all the 

 hajmoglobin out of it, leaving it white and pulpy." Brief 

 mention is made of the habit of the land planarians of 

 secreting a mucous thread and hanging from it as a mollusc 

 does. Finally, the method of movement of Bipalium with 

 the head raised and waved from side to side as the animal 

 proceeds is described. A bibliography of previous literature 

 is given. 



In another paper Moseley ('77, pp. 273, 271) gives an 

 account of the movements and general habits of Geoplaua 

 11 a V a, a Brazilian species. This species was found to keep 

 in shaded and moderately lighted places. The direction of 

 the ciliary currents was tested by placing small bits of paper 

 on the surface of the body, and it was found that when the 

 aninuil was in active movement the effective beat of the 

 cilia on the anterior part of the dorsal surface was forward 

 and outward, while on the posterior portion of the dorsal 

 sui'face the beating was backward and outward. The 

 currents on the ventral surface were always straight back- 

 ward. The author concludes that the function of the cilia 

 on the dorsal surface is to quickly remove foreign bodies. 

 When the organism was at rest there was no movement of 

 the dorsal cilia; "the animal moves to a large extent by 

 muscular action, the body alternately contracting and ex- 

 piinding during motion. When moving it lifted its anterior 



