REGENERATION OF PLEUROTRICHA. 



173 



is finely granular. The changes here appear more like those of 

 a degenerative than those of a physiological process and may have 

 been present at the time the animal was operated upon. 



In the twenty other experiments there were two macronuclei 



TABLE V. 



LONGITUDINAL CUTS. 



and two micronuclei, the number normally and most constantly 

 found in this strain of animals. 



In Table VI. are recorded the observations made on twelve 

 animals, descendants of merozoa and selected from various 

 generations from the second to the thirty-fifth. In all of these 

 animals there were two macronuclei and two micronuclei. 



TABLE VI. 



Thus, the evidence furnished by these experiments is that 

 merotomy does not produce any change in the normal number 

 of macronuclei and micronuclei, either in the merozoon or in its 

 descendants as far as the thirty-fifth generation. The occurrence 

 of cells with more micronuclei than macronuclei are more readily 

 explained as having been mechanically produced by the opera- 

 tion itself or as the manifestation of an abnormal cell process 

 that may have existed before merotomy was performed, as such 

 cells are found in normal laboratory cultures of this animal. 



