Many views have been put forward as to the morphological relationship between the two types of person in the Hydromedusae.
On this point the following theories have been put forward.
Balfour put forward the view that the polyp was the more primitive type, and that the medusa is a special modification of the polyp for reproductive purposes, the result of division of labour in a polypcolony, whereby special reproductive persons become detached and acquire organs of locomotion for spreading the species.
Like his predecessor, he enjoyed the protection and support of the Polish king, Sigismund III., and was strong enough to ii., compel Shuiski to abdicate; but as soon as the throne was vacant Sigismund put forward as a candidate his own son, Wladislaus.
A natural classification of the Hydroidea has yet to be put forward.
