PROPAGATION BY BUDS. 73 



and ravenously devouring whatever prey they can 

 master. 



The special habitation of the Trumpet- Hydra seems 

 to be the inner surface, and especially the upper cavity 

 of empty oyster- and other bivalve shells. It diffuses 

 itself anywhere, however, provided the position be fa- 

 vourable ; but certainly best when pendent and under 

 shelter. " Notwithstanding this, it will be seen, as we 

 proceed, that the position of the original founder of 

 the colony must be accidental times out of number, 

 and that the dispersion of the progeny is dependent 

 on a great variety of circumstances. 



A still more remarkable phenomenon in the history 

 of these wonderful beings remains to be considered. 

 It may be stated, as a general law of nature, that ani- 

 mals only become capable of producing offspring when 

 they have arrived at a state of maturity : the cater- 

 pillar is not permitted to lay eggs until it has attained 

 the form of the perfect Butterfly ; the tadpole only 

 acquires the power of reproducing its kind when it 

 has gained the limbs and stature of the adult Frog : 

 in short, it has hitherto been looked upon as an 

 established axiom, that no larva or immature creature 

 can be prolific. Now, as the reader will perceive 

 further on, the Hydra tuba is not an adult animal, but 

 only in a preparatory or larval condition, and yet, 

 strange to say, it is enabled to furnish progeny and 

 multiply its race to an extent that seems quite in- 

 definite. 



On watching closely one of these remarkable beings 

 while in a well-fed and vigorous condition, the aqua- 

 riist will not fail to observe, that at times little buds, 



