Abstracted by Donnell Brooks Young, author 

 Carleton College, Northfield, Minnesota. 



A contribution to the morphology and physiology of the genus 



Uronychia. 



This paper records the results of regeneration experiments on 

 the hypotrich Uronychia. It shows that in this form the power 

 to regenerate parts lost by cutting or other injury is not dependent 

 upon the presence of a micronucleus, although parts without a 

 micronucleus do not divide. The ability to regenerate increases 

 with age, being least just after division and greatest just before 

 the process starts. The large cirri are so highly differentiated 

 that injury to them alone does not result in their regeneration, 

 although they do regenerate if the body of the animal is injured. 

 Injuries to the micronucleus frequently result in the formation of 

 monsters. 



