330 GRIFFIN. 



In the elongation of the groups of new cirri, the posterior one of each 

 group remains at the point where it appeared while the anterior ones 

 are shifted forward. In the ease of the triple groups, the two anterior 

 I'lrri remain close together and one behind the other until the rearrange- 

 ment is nearly completed. As the new cirri approach the anterior limits 

 of each daughter body, the anterior portions of the depressions become 

 separated from the posterior, or open upon one side (Plate VIII, figures 

 34 and 35), and then gradually are obliterated. A curious feature of 

 this process is that the left margin of the depression seems always to 

 1)6 the first to disappear. The portions of the grooves remaining about 

 the posterior cirri now assume the form and position characteristic of 

 the adult Euplotes. (Plate I, figure 1.) The anterior cirrus of group 

 B is the first to become independent of its mate. The two of group D 

 next lose their alignment, and separate. Those of group C follow, while 

 the anterior pairs of B and A retain nearly the original relations until 

 the development of the daughter bodies lacks little of being complete. 



While the new cirri are developing the old ones are being absorbed, one 

 by one. The absorption begins as soon as the new cirri appear. The 

 first to go seems to be anal I (Plate VIII, figure 33), although 8 and 9 

 may disappear at the same time. Anal II follows ne.xt (Plate VI, figure 

 35), and then anal V (Plate VIII, figures 34 and 36); 8 and 9 are 

 sure to be gone by this time, and usually several of the frontal cirri, 

 as is shown by fixgure 34, Plate VIII, where 4, 5, 6, and 7 have disappeared. 

 At the time this speciinen had reached the stage shown by figure 36, 

 cirri 1 and 10 and one of the right marginals had also gone. After this 

 it is only a matter of minutes before the remainder of the old cirri, 

 frontals, anals, and marginals, disappear, so that by the time division 

 is completed not one of the old cirri of the mother body remains. 



The final disposition of the new cirri can be followed better from Plat« 

 VIII, figures 33 and 36, than from any description. The most peculiar 

 thing in the course of this development is the manner in which the new 

 ■ frontal cirrus 4 of each body develops. This is quite different in the 

 two bodies, yet essentially similar. The single cirrus P which develops 

 just back of frontal 7 has been mentioned. This increases in size at the 

 same rate as the outer new cirri, and without much change of position 

 becomes the new frontal 4 of the anterior daughter body. 



The corresponding cirrus in the posterior daughter body springs from 

 the inner side of the peristomial aperture as soon as this reopens. (Plate 

 VI, figures 23 and 25.) It is extremely active in its movements from 

 the first, waving with a spiral motion so rapid and continued as to suggest 

 that it is actively engaged in directing food into the new peristome. 

 That this is not the case is proven by the complete absence of food balls 

 from the peristomial invagination. For a long time this motile organ, 

 apparently a part of the buccal apparatus, proved very puzzling. But, 



