POLYMORPHISM 



355 



-.. b 



s b 



r.z. J 



FIG. 221. Diagram of a Siphonophore colony, b, Float; *.&, swimming bell- 

 m, mouth; w.z., trophic polyp; p.z., protective zooid; rz\ rz\ n* reproductive 

 zooids; t, tentacles. (From Galloway, after Lang.) 



