OCEAN LIFE. 9 



Instead, however, of falling to the bottom, as so apparently 

 helpless a particle of jelly might be expected to do, the cease- 

 less vibration of the cilia upon its surface propels it rapidly 

 along, until, being removed to a considerable distance from its 

 original, it attaches itself to a proper object, and, losing the now 

 useless locomotive cilia, it becomes fixed and motionless, and 

 develops within its substance the skeleton peculiar to its species, 

 exhibiting by degrees the form of the individual from which it 

 sprung. 



It is curious to observe the remarkable exception which 

 Sponges exhibit to the usual phenomena witnessed in the repro- 

 duction of animals, the object of which is evident as the result is 

 admirable. The parent Sponge, deprived of all power of move- 

 ment, would obviously be incapable of dispersing to a distance 

 the numerous progeny which it furnishes. They must inevitably 

 have accumulated in the immediate vicinity of their place of 

 birth, without the possibility of their distribution to other locali- 

 ties. 



The seeds of vegetables, sometimes winged and plumed for the 

 purpose, are blown about by the winds, or transported by various 

 agencies to distant places ; but in the present instance, the still 

 waters in which Sponges grow would not have served to trans- 

 port their progeny elsewhere ; and germs so soft and delicate 

 could hardly be removed by other creatures. Instead, therefore, 

 of being helpless at their birth, the young Sponges can, by means 

 of their cilia, row themselves about at pleasure, and enjoy for a 

 period, powers of locomotion denied to their adult state. 



ZOOPHYTES OF OLD AUTHORS. 



POLYPS are gelatinous, oblong, or conical animals, with a con- 

 tractile body, an intestinal cavity, and an oval aperture, which 

 is surrounded by a circlet of arms or tentacles. Besides these 

 arms, there are no special organs of sense, at least in the greater 



2 " 



