“110 THE BEAUTIES OF NATURE CHAP. 
At the same time transverse wrinkles (¢) 
are formed round the body, first near the 
free extremity and then gradually descend- 
ing. They become deeper and deeper, and 
develop lobes or divisions one under the other, 
4 
Veer 
ee 
( 
Fig. 5. — Medusa aurita, and progressive stages of development. 
as at 5. After a while the top ring (and 
subsequently the others one by one) detaches 
itself, swims away, and gradually develops 
into a Medusa (6). Thus, then, the life-his- 
tory is very similar to that of the Hydroids, 
only that while in the Hydroids the fixed 
condition is the more permanent, and the free 
