FORMATION OF MEDUSA FROM THEM. 231 



increased in numbers. It is probable, however, that 

 the long continuance in the state of buds was owing 

 to artificial confinement, and that in freedom the buds 

 regularly develope perfect Medusae in their season. 



The mode in which perfect Medusae arise from the 

 buds is not the least remarkable phase of this sin- 

 gular history. When a bud has reached a proper 

 size it becomes cylindrical, elongated, and much dimi- 

 nished in diameter. At this stage transverse wrinkles 

 begin to appear at regular intervals, commencing near 

 the top, and gradually extending downwards. As the 

 operation proceeds, the uppermost wrinkles become 

 deeper, dividing the body into ring-like segments. The 

 tentacula gradually waste away, and the uppermost 

 ring acquires a border formed of eight equidistant lobes 

 or rays. This process goes on ; 

 ring after ring is bordered with 

 rays, and these rings begin 

 gradually to separate at the 

 edges, till the upper portion of 

 the cylinder resembles a num- 

 ber of shallow cups piled one 

 in another. As the furrows be- 

 tween them become deeper, the 

 rings acquire greater powers 

 of mobility, and at length an 



independent life is developed in each. The uppermost 

 segment falls off, and immediately assumes the swim- 

 ming habits of a young Medusa, but is only gradually 

 moulded to its perfect form. The next segment fol- 

 lows : and thus the cylinder continues to form and to 



