No. 3-] MORPHOLOGY OF THE STENTORS. 509 



The changes in the stripes during fission are an index 

 to the extraordinary alterations in the contours of the animal. 

 The most obvious modifications are in width and length. The 

 granular stripes of the new frontal field are about half the 

 breadth of those of the ramifying zone from which they are 

 derived ; while the granular stripes at the posterior end of the 

 distal zooid become at length scarce a fifth of their former 

 breadth. Their attenuation has kept pace with the constriction, 

 and what they have lost in breadth they have gained in length. 

 That the stripes are viscous like the rest of the cytoplasm, and 

 have been drawn down to greater fineness by the elongation of 

 the portion they cover, seems to me to explain sufficiently 

 their attenuation. Another explanation must be found for the 

 narrowing of stripes in the new frontal field ; for here certainly 

 no lengthening of stripes takes place. I have postulated an 

 increase in the number of striae through the bisection of each 

 granular stripe by a clear stripe. Schuberg (p. 227), although 

 taking note of the increase in superficial extent of the new 

 frontal field, nevertheless says : " Eine Vermehrung der 

 Korperstreifen innerhalb derselben \i. e., the frontal field] hat 

 dabei ebensowenig wie bisher statt. . . . Die Zahl der Streifen, 

 welche durch das Wachsthum der neuen Zone nach rechts und 

 links im Ganzen durchquert wurden, betragt zwischen 30-40, 

 was denjenigen auf dem Peristom ausgebildeter Thiere ent- 

 spricht." Now, as the number of granular stripes in the 

 ramifying zone varies, according to Schuberg, from 20 to 40, 

 the number of stripes in the new frontal field must also be 

 variable, and nothing short of counting in the living animal the 

 number of stripes enclosed at the outset by the new zone, and 

 again counting them in the fully-elaborated frontal field, and 

 finding the numbers to agree, would warrant Schuberg's 

 statement. I admit that my own view of the reduplication of 

 stripes is based — not upon an actual count, for I have found 

 that impossible — but upon their much greater fineness in the 

 fully-formed frontal field. 



The formation of the new ramifying zones is worthy of 

 notice. That of the proximal zooid is nothing more than the 

 posterior portion of the original ramifying zone, as will be seen 



