MORGAX. 



[VOL. II. 



f .6 X .22 



Feb. 4. -I .85 x .28 

 [ .6 x .23 



ANTERIOR PIECES OF HALF SIZE OR LESS. 

 Feb. 10. 



.85 x .32 

 .76 x .28 



r 



Feb. 6. 



f .6 

 .6 





 x 



23 

 3 



Feb. 13. 



.68 x .2 



7 < -34 



.8 x .35 x .25 



.9 X .28 X .2 



.64 x .28 



1. 12 X .39 

 [ 1.2 X .28 



Feb. 20. 



.96 x .36 

 .00 x .39 

 .04 x .32 

 .00 x .40 

 .00 x .40 

 .00 x .39 

 9 x -36 



It will be seen from this table that, after feeding, the 

 stentors from anterior pieces grow larger. The increase takes 

 place both in the peristome and in the length of the piece, so 

 that the proportionate size of the disk to the rest of the piece 

 remains about the same. The new stentors had begun to 

 divide on February 13, and by February 20 there were about 

 twice as many present as at first. They have, however, about 

 the same proportionate size as at first. The question arises 

 whether in the normal stentor the ratio of the breadth of the 

 disk to the length of the pieces may not be less than in very 

 large individuals. I measured some of the smaller individuals 

 found in the aquaria with the larger ones and obtained the 

 following results: 1.04 x .36 ; .72 x .26; .7 x .28 ; .72 x .3 ; 

 .9 x .38 x .2 ; i.i x .28 ; .9 x .36 x .2 ; .98 x .28. There is 

 seen to be some variation in the relative size of the length to 

 the breadth ; that is due in part to the individuals not always 

 expanding to the same extent, and also in part to some of the 

 measurements of the peristome not having been made in 

 the widest part, but there are also actual differences, as some 

 very careful measurements have shown. It will be seen that 

 while in large stentors the greatest breadth of the peristome 

 is about one-fourth, or nearly so, of the total length, in the 

 small individuals the breadth is more nearly one-third of the 

 length ; therefore the peristome is proportionally somewhat 

 larger for smaller pieces. Comparing these measurements 

 with those of the sizes of individuals derived from pieces of 

 the anterior end, we see that they have reached in several cases 

 the characteristic form for a small individual. Since there is 



