232 GROWTH OF POLYPES SIMILAR. 



throw off. one after another, the little creatures destined 

 henceforth to act according to their " own sweet will," 

 and in their proper season to produce new germs or 

 buds, from which other young Medusae shall arise. 

 During this process of throwing off young Medusa in 

 the upper part of the column, its lower part continues 

 to grow, and to become ringed as it grows ; and Dr. 

 Reid counted on a single column thirty or forty rings 

 thus in process of conversion at the same time. Nor 

 is this all : the same accurate observer assures us, that 

 in no case does the formation of rings continue to the 

 base of the column ; but that after a time the ringing 

 process ceases ; the stump which remains throws out 

 tentacula from its apex, and continues to live as a 

 bud, ready, it would appear, either to form new stolons, 

 or buds, or to resume the functions of a parent, and 

 throw off a new batch of young ones. The whole is 

 so similar to what takes place in the vegetable king- 

 dom, where a season of rest follows the season of blos- 

 soms, that we are tempted to suppose a somewhat closer 

 connection than one of mere analogy between the two 

 operations. Among animals the facts now stated are 

 by no means isolated. A very similar mode of growth 

 and propagation is found among the compound Polypes, 

 whose gemmules, like those of the Medusae, are at first 

 free, and moved by cilia ; afterwards attached, and 

 budding forth with a plant-like body. And, omitting 

 differences of organization, the great difference which 

 strikes us in the process is, that in the Polype the fully- 

 developed animal continues throughout its life attached 

 to the trunk, or polypidom ; while in the Medusae the 



