THE FLAXEN FLTJSTRA. 97 



its mature state, it occupies the broad upper part 

 of the cell. When it has thus gained the summit, 

 we may observe a distinct wide helmet-shaped 

 capsule, surrounding it and separating it from the 

 cavity of the cell. On examining the egg within 

 this capsule by the microscope, we perceive its 

 cilia in rapid motion, and Dr. Grant has frequently 

 seen the egg in this situation contract itself in 

 different directions, shrink back in its capsule, and 

 exhibit many signs of irritability before its final 

 escape. The helmet-shaped capsule is open at the 

 top, and connected with the aperture of the cell, so 

 that the egg readily escapes by' contracting its body 

 and moving its cilia. On escaping from the cell, 

 the egg glides to and fro by their action, and after 

 fixing, it is changed into a single complete cell, from 

 which new cells shoot forward. Polyps make their 

 appearance in short sacs at the bottom of the new 

 cells, when they are sufficiently forward to protect 

 them. When the egg has escaped from the cell, the 

 dark round spot in the centre of the cell enlarges, 

 and the new polyps shoot out from that point, so 

 that at the proper season we may observe young 

 polyps in every situation of the branches ; the whole 

 of the old cells are thus never found entirely deserted, 

 the same cells may repeatedly produce eggs and 

 polyps, and the whole zoophyte retain its energy 

 for several seasons. 



With regard to the cells of these polyps, it must 

 be observed that they constitute an integral part of 



