76 E. A. ANDREWS. 



attachment there were two scars left on base of tube sac, one for 

 each of the two secessive periods of attachment of the animal to 

 the base of the same dwelling. 



Upon swimming up to the top of the tube to escape, as is 

 normal, the free swimmer now met with resistance as before 

 but for some reason the tube was not entirely closed as it seems 

 to have been the day before, possibly the force exerted by the 

 pushing of the lobes of the animal the day before had some effect 

 in changing the character of the closure of the tube. At all 

 events the free swimmer was finally able to force its front end 

 out of the tube through a minute orifice on one side back of the 

 tip so that by 8:45 it was seen escaping from the tube (Fig. 7). 

 However, the escape was but incomplete since the hole was 

 minute and the animal did not succeed in propelling its entire 

 length through; on the contrary, more than half its bulk re- 

 mained behind within the tube (Fig. 7) and the body was 

 constricted to a very narrow waist when passing through the 

 narrow hole, and was, as it were, cut almost into two with a 

 very narrow pedicle connecting the swimming part outside the 

 tube with the enlarged part within the tube. What abnormal 

 conditions here prevailed it was not determined, but one factor 

 in the failure to progress completely out of the tube seems to 

 have been the abnormal state of the foot end. This swelled 

 up into globular form and lost much of its normal organization, 

 receding into a more fluid phase. The contents slowly revolved 

 in flow and the protoplasm seemed more dead than living. 

 Nevertheless the cilia continued to cause the mass to revolve 

 for three and a half hours before dissolution of the ectosarc 

 resulted. 



Meantime, for nearly two hours, the anterior part of the 

 animal now outside the tube continued to swim with its numerous 

 rows of cilia and exerted strain upon the part within the tube; 

 this gradually led to the pulling out of a lengthening isthmus or 

 cylindrical waist between the active outside and the passive 

 inside swollen part. The base of the outside part became 

 pinched off nearly to complete severance from the rest. It 

 formed an oblique base of ragged form sending out pseudopodial 

 processes but ever at one corner, continuous with the hind part 



