SEXUAL REPRODUCTION. 97 



of PHYLACTOL^MATA the colonies are loco- 

 motive, the former moving by the aid of 

 " Vibracula," and the latter with a creeping 

 motion. 



Loxosoma non-colonial. InLoxosoma 

 (Endoprocta) we have the only known single 

 Polyzoon. In this genus, buds are formed, 

 but detach early. It is found commensal on 

 marine worms. 



Besides the colony budding, bads called 

 " Statoblasts " are formed on the Funiculus 

 and detached, being set free only on the decay 

 of the Polypides. 



Sexual reproduction. In the sexual 

 method of reproduction, each individual 

 possesses both male and female elements. 

 These are situated within the body-cavity, the 

 ovaries on the body- wall in the upper part of 

 it, and the male cells on the Funiculus. Both 

 elements are formed by a modification of the 

 cells of the coenosarcal layer lining the cavity. 

 In only a few species does there appear to be 

 any exit from this cavity It is therefore 

 inferred that fertilization usually takes place 

 within it. At the same time, it is has been 



