2C>6 



C. M. CHILD. 



through the body-wall. The body-wall becomes thinner at the 

 oral end (Fig. 9) and tentacle-buds appear (Fig. 10), but these 

 usually do not develop beyond the stage shown in Fig. 10. 

 Occasionally they reach a length of 23 mm., but further than 

 this their development never proceeds. The distension gradu- 

 ally decreases again after a week or two and the tentacles which 



FIG. 8. 



FIG. 9. 



FIG. 10. 



FIG. ii. 



FIG. 12. 



FIG. 7. 



FIG. 15, 



had attained a length of 23 mm. decrease in size to mere buds. 

 In cases where the tentacles never develop beyond the stage 

 represented in Fig. 10 they are scarcely visible at all after two 

 or three weeks. 



In some pieces, however, closure of the aboral end occurs 

 sooner or later. This result may be attained in either of two ways- 

 In one case the aboral cut surfaces of the oesophagus and body- 

 wall fail to come into contact (Fig. 1 1) and the aboral end closes 

 in the usual manner by union of the cut surfaces of the body- 



