364 



EVENINGS AT THE MICEOSCOPE. 



fyiiig power which you arc at pi-esent using, that a 

 clear fluid is moving rapidly within all these canals, 

 carrying minute grannies ; not with an even forward 

 current, but with an irregular jerking vacillating move- 

 ment, as if several conflicting eddies Avere in the stream. 

 Yet we discern that, on the whole, the granules 



are moved forward ; passing 

 from the centre of radiation 

 towards the margin, when we 

 see them slip into the marginal 

 canal from tlie several mouths 

 of the radiating canals. 



This is a ver}'- simple and rudi- 

 mentajy blood-sjstem. There 

 is here no heart with its pulsa- 

 tions, no proper ai'teries or veins, 

 no lungs for oxvijenation : but 

 the products of digestion are 

 tliemselves thus circulated 

 through the system. And this 

 brinsrs me back to tlie central 

 point, whence you see depend- 

 ing the curious organ I spoke 

 of. A long cylinder of highly 

 moveable and evidently sensi- 

 tive flesh hangs down from the 

 middle of the roof exactly like 

 the clapper of a bell ; and, as 

 if to add to the resemblance, this same clapper is sus- 

 pended by a narrow cord, and is terminated by a knob. 

 Sometimes this whole organ is allowed to hang 

 about as low as the edge of the bell ; then it gradually 

 lengthens to twice, thrice, nay to five times that 



SAnsiA. 



