GENERAL CONSIDERATIONS 



17 



trans fuga (Fig. 1) — is cut transversely through the center so that ap- 

 proximately half of the thirteen or fourteen beads which constitute the 



Figure 2. Uronychia trans juga, merotomy and regeneration. 1. Cell immediately after 

 division, cut as indicated; 2, Fragment A of 1, three days after the operation, no re- 

 generation; 3. cell cut five hours after division; 4, fragment A of 3, three days after 

 operation, no regeneration; 5, cell cut at beginning of division as indicated into prospec- 

 tive fragment A, B, and C; A', B', C, fragments A, B, and C twenty-four hours after 

 the operation; fragment A regenerated into a normal but amicronucleate individual 

 (A') ; B, C, divided in the original division plane forming a normal individual C and 

 a minute but normal individual B'. (After Calkins, 1933-) 



macronucleus are left in each of the two halves, while the micronucleus 

 is left undisturbed in one half. If the operation is made on an individual 

 three to five hours, or less after the last previous division, the fragment 



