MOVEMENTS, EIC, OF FUESII-WATEU PLANARIANS. 517 



extfoinity offceiij and moved it to aud ffo as it" to fee 



or see its way/' " When the anterior extremity of the body 

 was cut off the remainder of the animal seemed still to move 

 with definite purpose, avoiding obstacles and retreating- from 

 the light; while the cut end was raised and thrust in various 

 directions as if to search for an object on which to climb." 



In a brief note Zacharias ('88) mentions the occurrence of 

 Geodesmus terrestris between the lamellic of Agaricus 

 deliciosus. Particular points mentioned are : the slow 

 movement^ characterised by the raised anterior end, aud the 

 hanging by a mucous thread after passing over the edge of 

 a glass plate. Light stimulation of the anterior end with a 

 needle induces a very strong contraction of the whole body. 



(Jamble ('03), in a systematic paper on marine 'i\xrbel- 

 laria, describes briefly the movements of a number of 

 species of rhabdocujles and triclads. 



Lang ('84), in his monograph on the polyclads, devotes a 

 chapter to the habits, movements, and natural history of this 

 group of })lanarians (loc. cit., pp. Goi — Gil). While not 

 done particularly from the physiological standpoint and not 

 treating the subject experimentally, this w(jrk contains 

 numerous valuable observations. Points especially treated 

 are the habitat, colouration, food and method of feeding, 

 defecation, movements, including swimming, copulation, 

 respiration, regeneration, growth, and duration of life. The 

 details iu the behaviour of the polyclads recorded in this 

 monograph will be discussed later in connection with the 

 points on which they have direct bearing. 



The most important paper dealing with the movements 

 and general behaviour of planarians which I Iiave been able 

 to find in the literature is that of Lehuert ('91). This work 

 is principally devoted to an account of the biology of three 

 fornjs of land planarians, viz. Bipalium kewense, B. 

 keweuse var. viridis, and Geodesmus bilineatus. 

 Besides the work on these land forms, Lehnert also made 

 some comparative studies on several fresh-water dendroceeles 

 aud rhabdocoeles. He gives au admirably full and detailed 



