OF POLYPES. 



51 



empty cells after the escape of tlie ova. In the empty cells from wLich the 

 ova have escaped, we frequently observe a few remains of the former polypus, 

 lying at the place where the body of the polypus bifurcated, and where the prin- 

 cipal connection seems to exist between the polypus and the axis ; we likewise 

 perceive numerous nionades and other animalcules busily employed in consum- 

 ing the remains of the dead polypus. The ovum, even before arriving at ma- 

 turity, exhibits very obvious signs of irritability, frequently contracting different 

 parts of its surface, and shrinking backward in its cell ; the cilia on its surface 

 are likewise observed in rapid motion within the cell, as in the ciliated ova of 

 other zoophytes. The matuie ova are often found with their small end pro- 

 jecting from the opening of the cells, and their final escape is aided by the in- 

 cessant vibrations of the cilia covering their surface, by the ova contracting them- 

 selves in their lateral direction, by the waves agitating the branches of the flus- 

 tra, and by the same incomprehensible laws which regulate the formation and 

 growth of the ova, and the whole economy of this zoophyte." — Edin. New. Phil. 

 Journ. iii. II 6-7. 



Egg of Alcyoxidium hirsuti'm. 



