182 



THE ORGANIZATION 



among the members of this class : the one a Starfish, (figs. 109, 

 110, and 111,) in which the multiplication of parts is carried out 



to the greatest degree, 

 and the other, one of 

 the Trepangs, (figs. 

 114, 115, 116,) in 

 which the repetitions 

 are the least in num- 

 ber. In these two 

 foreshortened views 

 (fig. Ill and fig. 115) 



of the animals in 



i 



question, you may see 

 at a glance the differ- 

 & ence in the degree of 

 repetition ; but you 

 will understand better 

 what organs are af- 

 fected thus in both. 



Fig. in. after I have illustrated 



them from the most natural point of view. I merely draw your 

 attention to these views now, because one of them, the Starfish, 

 usually presents itself to the observer in this position, (fig. 109,) 

 on account of its peculiar form, which can hardly be said, in 

 common parlance, to have a profile view. When we speak of 



Fig. 111. Asteracanthion rubens. M. and Tr. A diagramic, foreshortened 

 view of the anterior face, to exhibit the relations of the various organs. The 

 median arm is below, and the madreporiform body (jri) is in the middle line 

 above. The ends of the arms are left out of view, st, the stomach ; rf', the 

 puckered prolongations from st ; sft, sfl, the bases of st 1 , the latter being cut 

 away ; aq, the aquiferous ring about the mouth ; aq 1 , o<? 2 , the aquiferous canals ; 

 7H 1 , the madreporic canal ; m, the madreporiform body ; b, the so-called circular 

 canal of the blood circulation ; 6 1 , b' 2 , the points where b gives off canals (i 5 ) to 

 the arms ; J 3 , b*, branches from such as 5 5 , which spread over the puckered pro- 

 longations from the stomach ; n, the nervous ring about the mouth ; n l , n 2 , 

 branches from n ; r, r%, the reproductive organs ; r 1 , the point where the eggs 

 escape. Original. 



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