184 Voracity of the Asplanchna , and its Stomach Currents. 



so as to form one triangular bag. The Euglena was elongated 

 into a cylinder -with a pointed tail. At another time the 

 ciliary motions of the stomach made it spin round and round 

 about its long axis.'" 



My present object is to call particular attention to the 

 ciliary stomach currents last mentioned, as I have seen them 

 more strikingly displayed in the asplanchna than.iu any other 

 rotifer. It would seem as if the whole surface of the stomach 

 were lined with cilia in active motion, and the direction of the 

 currents they occasion, depends chiefly upon the gaps that 

 occur in the masses of food. The motions of the creature 

 agitate and constrict the stomach. Thus the food, when reduced 

 to a pulp, is easily divided into separate portions, and the spaces 

 between them form channels, down which the ciliary currents 

 rush. They are easily seen with a good £ or 3-th, but with 

 Smith and Beck's -j'oth, (and doubtless also with Powell and ' 

 Lealand's ^th), they are magnificent objects. It was with the 

 former glass I frequently viewed them, and I find on one occasion 

 the following note entered in my microscopic memorandum 

 book : — 



" The stomach of the asplanchna exhibits the ciliary motion 

 very finely — the food gets divided into separate masses, and in 

 the inter-spaces, the ciliary currents look like the confluence 

 of ten thousand waterfalls, and often form whirlpools in which 

 .small particles are hurled about with great velocity/' No 

 drawings can give anything like a picture of such movements ; 

 but a diagramatic sketch was made of the most singular, and I 

 find two closely curled Avhirlpools working away in juxtaposition, 

 and connected with two parallel currents about a seven 

 hundredth of an inch long, both of which were curled inwards 

 at the bottom, and sent up two steady streams, the tendency of 

 which was to cut another channel through the food mass, and 

 to keep its particles bathed incessantly on every side. 



Lower powers easily show that these currents exist, but 

 no idea can be formed of their beauty as a spectacle, unless 

 with such an object-glass as the yV.lli and careful illumination 

 with the achromatic condenser. As thus displayed it was one 

 of the most striking and memorable scenes of the microscope 

 that I have ever witnessed; Some other rotifers may answer 

 lie purpose as well as I he asplanchmi for showing these 



currents; but I have never met with one equal to it. Tho 



tissues are as Clear as our finest glass, and the stomach well- 

 situated. Slight compression should be employed, but not 

 enough to hurt the creature whose internal after-dinner arrangc- 

 it is intended to survey. 



