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. 
