WINTER EGG CAPSULE IN PLANARIA SIMPLISSISSIMA. 



227 



The planarian then moved slowly forward, the capsule passing 

 along through its body and out at the dorsal caudad region. 

 The rotation of the capsule in the body of the animal apparently 

 aided in breaking the wall of the cavity in which the capsule lay, 

 for there seemed to be no difficulty in the passage through the 

 posterior portion of the body and out near the tail (Fig. 4). 



The entire process of extrusion occupied only about thirty 

 minutes. 



The next day the wound where the capsule had originally lain 

 was partly closed by contraction of the surrounding tissue, and 

 the wound in the tail region made at the escape of the capsule 

 was obliterated almost entirely. 



I was interested to see if the same planarian forms more than 



Q 



W 



Fig. 4. 



VJ 



Fig. 5. 



one egg capsule, so isolated the animal I had been observing, 

 and examined it several times each day. 



In a week complete regeneration was effected. At the end of 

 twenty days from the time I had seen the first capsule, another 

 appeared, evidently formed during the night, and I had the good 

 fortune to observe its extrusion also. The movements were the 

 same as before observed, except that the capsule was extruded 

 on the right side of the body this time. 



Other planarians bearing capsules were observed, and in all 

 cases the capsule was rotated immediately before the extrusion 



The individual described previously, at the end of about three 

 weeks more, extruded a third capsule. 



Kept in a small vial on my desk for two months after this 

 extrusion, the planarian formed no more capsules. 



