ONTOGENESIS 139 



tacles, a mouth opens, and the bud becomes in all 

 respects an individual Hydra, able to carry on all the 

 functions of life. The process is completed by a 

 severing of the connection between bud and parent. 



Permanent Budding. In the majority of the 

 marine relatives of the Hydra the buds formed in 

 this way do not separate from the parent stem, but 



FIG. 53. Portion of Syllis ramosa, an annelid worm in which the col- 

 lateral buds branch repeatedly. (M'Intosh.) 



remain attached, forming colonies of many indi- 

 viduals. Such a condition of persistent budding is 

 characteristic of plants, but occurs as well in many 

 Protozoa. In some instances the buds run together 

 in such a fashion that it is impossible to discriminate 

 one individual from another. In Syllis we have a 

 highly organized worm that divides and subdivides, 

 like 'the branches of a tree, while individual heads 

 develop here and there. 



