1902.] NATURAL SCIENCES OF PHILADELPHIA. 769 



centrifugal growth the bud becomes sausage -shaped, and as long 

 as the diameter of the polyp (fig, 6). Soon after the bud reaches 

 the stage shown in this figure, it becomes detached from the polyp. 



Fig. 5. 



Bud three days old. En- Bud four days old. Ready for de- 



doderm isolated from that tachment. Showing interradial posi- 

 of parent by constriction of tion. 

 ectoderm. 



In only one instance was I so fortunate as to see this process 

 taking place. In this individual the bud was drawn out into a 

 long finger-like body, its distal end drooping almost to the ground. 

 Soon the ectodermal isthmus began to stretch out and dwindle in 

 diameter, until it was merely a thin stem of transparent protoplasm 

 (fig. 7). The bud seemed to be reaching out and trying to free 



Fig. 7. Fig. 8 



Another individual. Bud in Same bud fifteen minutes later, 



process of detachment, showing Bud settling down on distal end. 

 elongated ectodermal isthmus. 



itself from the limitations of its connection with the parent. This 

 stretching of the isthmus was brought about by constriction of the 

 tubular ectoderm, as by circular muscle fibres. When this slretcU- 



