DR Wright's observations. I7l 



stolons, which extended to some distance from the body be- 

 fore the new polype bodies sprouted from them, but in 

 that case also a prolongation of the intestinal clement 

 passed through the stolon from the old into the new body. 

 These new polypes were not young ; their production was a 

 simple increase of the individual, becoming afterwards a mul- 

 tiplication, either by accident, in some cases, or in others by 

 a natural process of absorption. The structure of the helian- 

 thoid zoophytes or Actinias was more complicated in its de- 

 velopment than that of the hydi^oid polypi, but it consists of 

 the same three elements. The dermal coat was succeeded by 

 the muscular element, which constituted the chief part of the 

 external wall of the body and tentacles, and then passed in- 

 ward to the stomach, in the form of septa or partitions, 

 which suspended that viscus in the centre of the body, and 

 divided the intervening spaces into numerous chambers. 

 The mucous or intestinal element existed as a jfiattened sac 

 or stomach, which appeared, when viewed edgeways, as a 

 mere line extending down about half the centre of the body. 

 The stomach communicated freely with the general cavity of 

 the body. This cavity, which corresponded to the water- 

 vascular system of the Acalephge, was single below, but as it 

 passed upward it formed a number of chambers divided from 

 each other by the septa before mentioned, and finally com- 

 municated with the tentacles, each chamber terminating in 

 the cavity of a single tentacle. 



"The whole of the general cavity and its chambers was 

 lined with cilia, by wliich a constant cii'culation of the fluid 

 was sustained, and the functions of nutrition, respiration, and 



