134 



Papers from the Department of Marine Biology. 



Table 1. — Record of experiment 4a, started September 30, 1913 (Jor 1 to 5 da ?/s)— Continued. 



[Forty disks each with all sense-organs removed from one side and with the halves insulated by 

 removal of 2 strips of subumbrella ectoderm. The letter C after the measurement for any 

 day indicates that the central cavity had been filled by the regenerated tissue.] 



Specimen. 



1 day. 



2 days. 



.3 days. 



4 days. 



5 daj's. 



No. 29 



Half w 

 Half w 



„ „„ /Half w 



N°- 30 JHalf w 



Half w 



Half w 



Half w: 



Half w 



/Half w 



\Half w 



Half w 



No. 31 

 No. 32 

 No. 33 

 No. 34 

 No. 35 

 No. 36 

 No. 37 

 No. 38 

 No. 39 

 No. 40 



Half w 



/Half w 



iHalf w 



Half w 



Half w 



Half w 



Half w 



Half w 



Half w 



/Half w 



[Half w 



Half w 



Half w 



Mean of all 



Half w 

 Half w 



th S. O . . . 



thout S. O 

 th S. O . . . 

 thout S. O 

 th S. O . . . 

 thout S. O 

 thS. O... 

 thout S. O 

 th S. O . . . 

 ithout S. O 

 th S. O . . . 

 thout S. O 

 thS. O... 

 thout S. O 

 th S. O . . . 

 thout S. O 

 ith S. O . . . 

 thout S 

 th S. O 

 thout S 

 thS. O... 

 thout S. O 

 th S. O . . . 

 thout S. O 

 observations: 



2.50 

 2.00 

 3.00 

 1.20 



O 



.00 



.00 



.00 



.25 



.75 



0.50 



2.00 



1.50 



3.00 



2.00 



3.75 



2.00 



2.75 



1.50 



3.75 

 3.00 

 3.55 

 2.00 

 3.00 

 2.25 



3.00 

 2.00 

 2.50 

 1.00 

 4.00 

 3.00 



4.50 



3.50 



3.75 



2.50 



5.00 



3.50 



6.50 



4.00 



4.50 



2.50 



6.00\, 



4.00/ 



Badly wrinkled. 



4.75 7 



3 . 25 5 



7.00\^ 

 5.00/'" 

 10.75 

 7.50 

 6.00 

 4.00 



001 

 50/^ 



Too badly wrinkled to measure new tissue. 



O. 



50 

 00 

 00 

 25 

 25 

 .00 



th S. O . . . 

 thout S. O . 



2.65 

 1.73 



8.25 

 5.00 

 4.00 

 3.00 

 2.25 

 1.75 

 5.25 

 3.00 

 6.00 

 4.75 



4.05 



2.87 



7.00 



5.50] 

 Badly folded. 

 7.501 



5.25 



5.75 

 4.06 



7.63 

 5.57 



9.00 

 6.36 



axea separation could be easily accomplished, but if a considerable 

 portion of the regenerating sheet was involved the specimen was 

 rendered useless for further study. 



The results of two typical experiments are shown in table 1. The 

 measurements are in millimeters. The upper figure for each date 

 shows the width of the sheet of tissue regenerated from the active half- 

 disk, the lower figure the width of that regenerated from the inactive 

 half -disk. When the sheet of new tissue had entirely closed over the 

 cavity in the center of the disk the point of closure remained recogniz- 

 able for at least a day, so that the measurements could readily be made 

 for those disks that had become closed since the time of the last meas- 

 urements. By the end of 24 hours after the new sheet of tissue was 

 completed the point of closure would be shifted until it came to lie in 

 the center of the disk. 



