ZOOLOGICAL SOCIETY BULLETIN 



1165 



A MKlRATINCi WHITE-ARMED ANEMONE 

 Note tile Ting of mucus left Ix'hiiul. 



direction and traveled two and a half inches 

 to No. 13; the following day it proceeded two 

 inches further to No. 14, the next day to No. 1.5. 



Without any rest the rambler now broke all 

 records and travelled four and a half inches 

 in one day, the longest single day's journey it 

 made during the period of observation (No. 

 16). The following day's work resulted in only 

 half an inch (No. 17) and two days were con- 

 sumed in making the ne.xt half inch to No. 18. 

 Another long trek followed this when four inch- 

 es were made in one day to No. 19, and on 

 the following daj' it nearlj' reversed its direc- 

 tion and made two more inches to No. 20. 

 Again altering the direction the anemone trav- 

 elled during the next day about two inches 

 further to No. 21, where it rested for 10 days. 



The next move was wholly unexpected from 

 such an energetic tourist, for in one day it 

 moved downward two inches to tlie bottom of 

 the tank (No. 22), at a distance of about six 

 and one half inches from its original starting 

 point. Apparently satisfied with the results 

 of its wanderings — though it is difficult to see 

 what advantage had been gained by the 

 procedure — it now settled down and remained 

 in this position for three months, when the ob- 

 servations were terminated. 



The entire distance traversed was about 

 forty-eight inches and eighty-two days were 

 occupied by the journey. Of this time, how- 

 ever, only twenty-four days were actually con- 

 sumed in travel; the remaining fifty-eight be- 

 ing spent in resting at various stoi)ping-places 

 along the way — a leisurely journey surely. 



It will be seen that the average distance 

 covered by its travels during these twentj'-four 

 da\'s of actual progress was two inches per 

 day. The shortest distance it was observed 

 to move during any one day was about half an 

 inch and the greatest single day's journey 

 four and a half inches. 



In the course of its meanderings tiiis ane- 

 mone progressed from the bottom of the jar 

 nearly to the top, the actual vertical distance 

 l)eing ten and a quarter inches, while the to- 

 tal distance from side to side was fifteen and 

 one quarter inches, or nearly one-third the cir- 

 cumference of the jar. ' 



The course was confined entirely to the side 

 of the jar away from the light, though why this 

 was the case is not evident since anemones are 

 frequently found on tlie light side of this same 

 jar. The direction of travel was altered de- 

 cidedly not less than fourteen times during the 

 course of twenty-one moves. As the anemone 

 has radial symmetry, and, therefore, no head, 

 it is not necessary for it to turn around before 

 starting off in a new direction, but the foot or 

 base seems merely to elongate in the direction 

 of travel. 



The motion is accomplished by the muscular 

 action of the adhesive base. Tliere are no def- 

 inite muscles in this organ, which usually 

 serves merely to attach the animal to the sub- 

 stratum, but there are muscle cells and it is 

 j)robably by an undulatory motion of these that 

 locomotion is accomplished. Apparently no 

 (jortion of the base was removed from the glass. 



When the animal is stationary for any length 

 of time the base becomes more or less circular 

 in outline, but in traveling it is somewhat 

 irregular in form and elongates in the direc- 

 tion of travel. When starting out to travel 

 from the resting condition, a rounded lobe ap- 

 pears on that side of the base in the direction 

 of travel, and sometimes several of these lobe:-i 

 appear in various positions as tliough the an- 

 imal were attempting to start off in several 

 directions at once. In such a case it was not 

 possible to observe why one of these lobes, 

 rather than another, should indicate the direc- 

 tion finally selected. When the direction of 

 travel is changed without entering the resting 

 condition, a portion of the base is extended in 

 the new direction and gradually the whole foot 

 becomes extended along the new line. 



If the sea-anemone remains stationary, evdn 

 for a day, a ring of thick mucus is secretfed 

 around the edge of the base and a thin 

 layer underneath. M'hen the animal moves 

 away this substance is left behind and may 



