PLATE 7 



EXPLANATION OF FIGURES 



27 to 32 represent two sections from each of three of the four parts into which 

 specimen no. 19, of table 5, divided. No. 19, before this division, was a very 

 large diglyphic specinr.en with twelve orange stripes and showing externally no 

 evidence of a previous division. Old regions are indicated by a greater number 

 of cycles of incomplete mesenteries, by the greater size of all mesenteries, and 

 by the presence of gonads attached to the larger mesenteries. The position in 

 the original polyp of the three specimens figured is indicated in table 5. The 

 regeneration period was from 34 to 37 days. For a full account of this case see 

 page 173. X 23. 



27 A far oral section of no. 19a. The fission plane passed through one com- 

 plete endocoel and one endocoel of the first incomplete grade. An unexplained 

 irregularity is seen in the incomplete mesenteries of the old part near the com- 

 plete bounding mesentery, c. 



28 A more aboral section of no. 19a. 



29 and 30 Respectively more oral and more aboral sections of no. 19d. 

 Division occurred in incomplete endocoels, one of first cycle and one of third cycle. 

 The small old bounding mesentery is in the position of one of the third incom.- 

 plete grade and far aborally is similar in size to others of that cycle. Its new 

 mate, barely indicated in figure 30, is smaller than the other new incomplete 

 mesenteries, all of which are of the first incomplete grade. At present, there- 

 fore, it appears to belong to the second incomplete cycle and it is so indicated 

 by the label. Probably its relation to the third cycle would be evident later. 



256 



