98 ZOOLOGICAL PHILOSOPHY 



Not only does it appear that the muscular system has ceased to 

 exist in the radiarians, but also there seems to be no sexual repro- 

 duction. There is indeed nothing to show or even to suggest that the 

 little oviform bodies, the clusters of which are called ovaries in these 

 animals, imdergo any fertihsation or are true eggs : this is rendered 

 still less probable by the fact that they are found in all individuals 

 alike. Hence I regard these little oviform bodies as already perfected 

 internal gemmules, and the clusters of them in special places as nature's 

 prehminary step towards sexual reproduction. 



The radiarians in their turn contribute to prove the general degrada- 

 tion of animal organisation ; for on reaching this class of animals 

 we find a shape and a new arrangement of the parts and organs that 

 are far removed from the animals of the preceding classes. Further- 

 more they appear to be destitute of feeling, muscular movement and 

 sexual reproduction ; among them the intestinal canal no longer has 

 two exits, the clusters of oviform corpuscles disappear, and the body 

 becomes completely gelatinous. 



Observation. 



It appears that in very imperfect animals such as the polyps and 

 radiarians, the centre of movement of the fluids does not exist except 

 in the alimentary canal ; it is here that it is first established, and it is 

 through this canal that the subtle surrounding fluids enter, mainly 

 for the purpose of stimulating the movement of the fluids which belong 

 to these animals themselves. What would plant life be without 

 external stimuli 1 What indeed would be the life of the most imperfect 

 animals without this factor, that is, without the caloric and electricity 

 of the environment ? 



The radiating form has no doubt been acquired as a consequence 

 of this method, which nature employs feebly at first in the polyps 

 and afterwards with greater vigour in the radiarians ; for the subtle 

 surrounding fluids which enter the ahmentary canal are expansive 

 and must by incessant repulsion from the centre towards every point 

 of the circumference give rise to this radiating arrangement of the 

 parts. 



This is the reason why in the radiarians the intestinal canal, although 

 still very imperfect, since it has usually only one opening, is none the 

 less provided with numerous radiating vascuhform and often branched 

 appendages. 



This again is no doubt the reason why in the soft radiarians, such as 

 jelly-fishes, etc., we may observe a continual isochronous movement, 

 a movement which very probably results from the alternative move- 

 ments of the masses of subtle fluids, which penetrate into the interior 



