96 G. H. PARKER 



with whitish markings; in some specimens they are tipped with 

 pink. They are at most sparsely ciliated and provided with 

 only a few nematocysts; their walls are thin. When cut they 

 may contract from a length of 15 cm. to 1.5 cm. 



If an expanded quiescent tentacle is touched near the tip with 

 a silver sound or a glass rod, the tentacle contracts, usually bend- 

 ing toward the stimulated side. The tentacle often sticks to the 

 object with which it is touched and it may in contracting thus exert 

 a considerable pull, showing that its surface is remarkably adhe- 

 sive and that its musculature is vigorous. This adhesiveness is 

 especially noteworthy in specimens with pink-tipped tentacles 

 and these individuals are known to adhere with the pedal disc 

 to the glass wall of an aquarium more tenaciously than those 

 without such coloration. 



If a strong stimulus is carefully given to a tentacle not closely 

 surrounded by others, the tentacle may contract without touch- 

 ing the others and yet these may also respond, thus giving evi- 

 dence of basal transmission from tentacle to tentacle. A ten- 

 tacle, if only once slightly touched, usually quickly returns to 

 its former position and quiescence. 



If a piece of crab-meat or fish-flesh is brought in contact with 

 a tentacle, it adheres firmly to the tentacle which quickly con- 

 tracts and is usually covered by several adjacent tentacles. The 

 piece of flesh is thus held on the disc while the mouth gradually 

 moves toward it and on reaching it swallows it. The animal 

 then slowly returns to a state of quiescent expansion. 



If a tentacle is cut off at almost any level, the stump at first 

 contracts but after a time again elongates to its appropriate 

 length, its cut end being closed by a nipple-shaped pucker 

 (Rand, '09, '15). The portion of the tentacle cut off, also 

 contracts and will remain indefinitely so at about one-third its 

 original length. Such a fragment of tentacle will live in sea- 

 water for several days. 



In specimens of Condylactis under natural conditions tentacles 

 are often seen marked with regions of pronounced constriction. 

 The portion of the tentacle distal to the constriction has been 

 often observed to be cast off and it is probable that these con- 



