ALTERNATE GENERATIONS. 959 
brilliant crested float. In this curious Acale- 
phian Hydroid, or Physalia, the individuality of 
function is even more marked than in the Hy- 
Physalia, or Portuguese Man-of-War. 
dractinia. As in the latter, some of the indi- 
viduals are Meduse-bearing, and others simple 
