HARDWICKE'S SCIENCE-GOSSIP. 



221 



took the form of fig. 146, the contents in the centre of 

 which (at h) were seen to move and turn half round 

 backwards and forwards, a motion frequently seen in 

 some rotifers, and in the ova of many small animals. 



In about three hours after the globular body (fig. 

 14S) had taken the form of fig. 146, a sort of tube or 

 shaft gradually protruded from the small end, and 

 soon displayed a row of rather long vibratile cilia 

 rotating on the top (fig. 147, a) ; the tube when elon- 

 gated was quite as long as the diameter of the oval- 

 shaped body, it was telescopic in form (fig. 147, b), 

 and could under alarm be quickly withdrawn into the 

 body. After the alarm had subsided the tube was 

 again cautiously put forth, when at first a sort of 



endeavoured to isolate some of them, and to get them 

 clear of the decaying vegetable matter in which they 

 were imbedded, but this proved very troublesome, 

 and I lost several in the attempt. The telescopic 

 form of the tube was very plainly seen either in act 

 of protrusion or retraction. At times the tube was 

 withdrawn (the rotifer remaining in a state of rest for 

 five or six hours), and then again put forth with the 

 ciliated lobes and continuing to rotate for the same 

 length of time ; sometimes I have known them to 

 continue in motion for over twelve hours. The last 

 I had under observation were four on one piece of the 

 Ricciajluitans, they kept alive and in motion without 

 any material change until May ist, when they all 





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Fig. 148. 



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Fig. 149 



horn, and sometimes two, were protruded at the top 

 (fig. 148, c) as a kind of feeler previous to again display- 

 ing the wheel of cilia. The jaws were placed at the 

 bottom of the tube (fig. 148, d) and very plainly 

 seen in motion in the act of feeding. The peculiarity 

 in the position of the jaws is quite a distinct feature 

 in the economy of this rotifer, as in every other rotifer 

 with which I am acquainted. The jaws are all situated 

 very close up to the ciliated lobes at the head, but 

 this one has them placed as shown in fig. 147 and 148, 

 close to the stomach, where the process of digestion 

 is seen taking place, in the backward and forward 

 motion before alluded to, hence none of the other 

 rotifers can be mistaken for this one. These rotifers 

 appear to be lodged in the cellular tissues of the plant, 

 and at times they protrude their ciliated lobes just out 

 of the cell of the plant, while their bodies remain 

 fixed. They are very small ; I make them out to be 

 only seven, one-thousandth of an inch in length. I 



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mUIL.X r'®€p:i&;^r-^4ii:^-^is^^::i^^ 



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Fig. ISO. 



withdrew into the telescopic tube, and remained on 

 the weed ; in this quiet state they continued for 

 fifteen days, when they again put forth a long and 

 transparent tube (fig. 149), but no cilia or wheels in 

 motion, the two horns were very prominent at the 

 top (fig. 149, rt). The jaws were not visible as before, 

 neither were the tubes of a telescopic form as at first ; 

 they appeared to be stretched out to their full length, 

 and the folds which formed the telescopic feature 



